Method of transmitting and receiving downlink signal between user equipment and base station in wireless communication system, and apparatus for supporting the same

ABSTRACT

Disclosed are a method of transmitting and receiving a downlink between a user equipment (UE) and a base station (BS) in a wireless communication system, and an apparatus for supporting the same. According to an embodiment applicable to the present disclosure, when the UE recognizes that plural transmission configuration indication (TCI) states related to one reference signal set are allocated to the UE through received downlink control information (DCI), the UE may receive/acquire a first physical downlink shared channel (PDSCH) scheduled by the DCI with high reliability.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Application No.PCT/KR2019/009395, filed on Jul. 29, 2019, which claims the benefit ofKorean Application No. 10-2018-0090980, filed on Aug. 3, 2018, andKorean Application No. 10-2018-0088863, filed on Jul. 30, 2018. Thedisclosures of the prior applications are incorporated by reference intheir entirety.

TECHNICAL FIELD

The following description relates to a wireless communication systemand, more particularly, to a method of transmitting and receiving adownlink between a user equipment (UE) and a base station in a wirelesscommunication system, and an apparatus for supporting the same.

BACKGROUND

Wireless access systems have been widely deployed to provide varioustypes of communication services such as voice or data. In general, awireless access system is a multiple access system that supportscommunication of multiple users by sharing available system resources (abandwidth, transmission power, etc.) among them. For example, multipleaccess systems include a Code Division Multiple Access (CDMA) system, aFrequency Division Multiple Access (FDMA) system, a Time DivisionMultiple Access (TDMA) system, an Orthogonal Frequency Division MultipleAccess (OFDMA) system, and a Single Carrier Frequency Division MultipleAccess (SC-FDMA) system.

As more communication devices have demanded higher communicationcapacity, enhanced mobile broadband (eMBB) communication technologyrelative to legacy radio access technology (RAT) has been introduced. Inaddition, a communication system considering services/UEs sensitive toreliability and latency as well as massive machine type communication(MTC) for providing various services anytime and anywhere by connectinga plurality of devices and objects to each other has been introduced.

Thus, eMBB communication, massive MTC, ultra-reliable and low-latencycommunication (URLLC), etc. have been introduced. In particular, variousconfigurations for a phase tracking reference signal (PT-RS) to estimatephase noise between a UE and base station (BS) in various frequencybands are under discussion in consideration of a signal transmission andreception method in the various frequency bands.

The present disclosure may be related to the following technicalconfigurations.

<Artificial Intelligence (AI)>

Artificial intelligence refers to the field of studying artificialintelligence or methodology for making artificial intelligence, andmachine learning refers to the field of defining various issues dealtwith in the field of artificial intelligence and studying methodologyfor solving the various issues. Machine learning is defined as analgorithm that enhances the performance of a certain task through asteady experience with the certain task.

An artificial neural network (ANN) is a model used in machine learningand may mean a whole model of problem-solving ability which is composedof artificial neurons (nodes) that form a network by synapticconnections. The artificial neural network can be defined by aconnection pattern between neurons in different layers, a learningprocess for updating model parameters, and an activation function forgenerating an output value.

The artificial neural network may include an input layer, an outputlayer, and optionally one or more hidden layers. Each layer includes oneor more neurons, and the artificial neural network may include a synapsethat links neurons to neurons. In the artificial neural network, eachneuron may output the function value of the activation function forinput signals, weights, and deflections input through the synapse.

Model parameters refer to parameters determined through learning andinclude a weight value of synaptic connection and deflection of neurons.A hyperparameter means a parameter to be set in the machine learningalgorithm before learning, and includes a learning rate, a repetitionnumber, a mini batch size, and an initialization function.

The purpose of the learning of the artificial neural network may be todetermine the model parameters that minimize a loss function. The lossfunction may be used as an index to determine optimal model parametersin the learning process of the artificial neural network.

Machine learning may be classified into supervised learning,unsupervised learning, and reinforcement learning according to alearning method.

The supervised learning may refer to a method of learning an artificialneural network in a state in which a label for learning data is given,and the label may mean the correct answer (or result value) that theartificial neural network must infer when the learning data is input tothe artificial neural network. The unsupervised learning may refer to amethod of learning an artificial neural network in a state in which alabel for learning data is not given. The reinforcement learning mayrefer to a learning method in which an agent defined in a certainenvironment learns to select a behavior or a behavior sequence thatmaximizes cumulative compensation in each state.

Machine learning, which is implemented as a deep neural network (DNN)including a plurality of hidden layers among artificial neural networks,is also referred to as deep learning, and the deep running is part ofmachine running. In the following, machine learning is used to mean deeprunning.

<Robot>

A robot may refer to a machine that automatically processes or operatesa given task by its own ability. In particular, a robot having afunction of recognizing an environment and performing aself-determination operation may be referred to as an intelligent robot.

Robots may be classified into industrial robots, medical robots, homerobots, military robots, and the like according to the use purpose orfield.

The robot includes a driving unit may include an actuator or a motor andmay perform various physical operations such as moving a robot joint. Inaddition, a movable robot may include a wheel, a brake, a propeller, andthe like in a driving unit, and may travel on the ground through thedriving unit or fly in the air.

<Self-Driving>

Self-driving refers to a technique of driving for oneself, and aself-driving vehicle refers to a vehicle that travels without anoperation of a user or with a minimum operation of a user.

For example, the self-driving may include a technology for maintaining alane while driving, a technology for automatically adjusting a speed,such as adaptive cruise control, a technique for automatically travelingalong a predetermined route, and a technology for automatically settingand traveling a route when a destination is set.

The vehicle may include a vehicle having only an internal combustionengine, a hybrid vehicle having an internal combustion engine and anelectric motor together, and an electric vehicle having only an electricmotor, and may include not only an automobile but also a train, amotorcycle, and the like.

At this time, the self-driving vehicle may be regarded as a robot havinga self-driving function.

<eXtended Reality (XR)>

Extended reality is collectively referred to as virtual reality (VR),augmented reality (AR), and mixed reality (MR). The VR technologyprovides a real-world object and background only as a CG image, the ARtechnology provides a virtual CG image on a real object image, and theMR technology is a computer graphic technology that mixes and combinesvirtual objects into the real world.

The MR technology is similar to the AR technology in that the realobject and the virtual object are shown together. However, in the ARtechnology, the virtual object is used in the form that complements thereal object, whereas in the MR technology, the virtual object and thereal object are used in an equal manner.

The XR technology may be applied to a head-mount display (HMD), ahead-up display (HUD), a mobile phone, a tablet PC, a laptop, a desktop,a TV, a digital signage, and the like. A device to which the XRtechnology is applied may be referred to as an XR device.

FIG. 1 illustrates an AI device 100 according to an embodiment of thepresent disclosure.

The AI device 100 may be implemented by a stationary device or a mobiledevice, such as a TV, a projector, a mobile phone, a smartphone, adesktop computer, a notebook, a digital broadcasting UE, a personaldigital assistant (PDA), a portable multimedia player (PMP), anavigation device, a tablet PC, a wearable device, a set-top box (STB),a DMB receiver, a radio, a washing machine, a refrigerator, a desktopcomputer, a digital signage, a robot, a vehicle, and the like.

Referring to FIG. 1, the AI device 100 may include a communication unit110, an input unit 120, a learning processor 130, a sensing unit 140, anoutput unit 150, a memory 170, and a processor 180.

The communication unit 110 may transmit and receive data to and fromexternal devices such as other AI devices 100 a to 100 e and the AIserver 200 by using wire/wireless communication technology. For example,the communication unit 110 may transmit and receive sensor information,a user input, a learning model, and a control signal to and fromexternal devices.

The communication technology used by the communication unit 110 includesGSM (Global System for Mobile communication), CDMA (Code Division MultiAccess), LTE (Long Term Evolution), 5G, WLAN (Wireless LAN), Wi-Fi(Wireless-Fidelity), Bluetooth™, RFID (Radio Frequency Identification),Infrared Data Association (IrDA), ZigBee, NFC (Near FieldCommunication), and the like.

The input unit 120 may acquire various kinds of data.

At this time, the input unit 120 may include a camera for inputting avideo signal, a microphone for receiving an audio signal, and a userinput unit for receiving information from a user. The camera or themicrophone may be treated as a sensor, and the signal acquired from thecamera or the microphone may be referred to as sensing data or sensorinformation.

The input unit 120 may acquire a learning data for model learning and aninput data to be used when an output is acquired by using learningmodel. The input unit 120 may acquire raw input data. In this case, theprocessor 180 or the learning processor 130 may extract an input featureby preprocessing the input data.

The learning processor 130 may learn a model composed of an artificialneural network by using learning data. The learned artificial neuralnetwork may be referred to as a learning model. The learning model maybe used to an infer result value for new input data rather than learningdata, and the inferred value may be used as a basis for determination toperform a certain operation.

At this time, the learning processor 130 may perform AI processingtogether with the learning processor 240 of the AI server 200.

At this time, the learning processor 130 may include a memory integratedor implemented in the AI device 100. Alternatively, the learningprocessor 130 may be implemented by using the memory 170, an externalmemory directly connected to the AI device 100, or a memory held in anexternal device.

The sensing unit 140 may acquire at least one of internal informationabout the AI device 100, ambient environment information about the AIdevice 100, and user information by using various sensors.

Examples of the sensors included in the sensing unit 140 may include aproximity sensor, an illuminance sensor, an acceleration sensor, amagnetic sensor, a gyro sensor, an inertial sensor, an RGB sensor, an IRsensor, a fingerprint recognition sensor, an ultrasonic sensor, anoptical sensor, a microphone, a lidar, and a radar.

The output unit 150 may generate an output related to a visual sense, anauditory sense, or a haptic sense.

At this time, the output unit 150 may include a display unit foroutputting time information, a speaker for outputting auditoryinformation, and a haptic module for outputting haptic information.

The memory 170 may store data that supports various functions of the AIdevice 100. For example, the memory 170 may store input data acquired bythe input unit 120, learning data, a learning model, a learning history,and the like.

The processor 180 may determine at least one executable operation of theAI device 100 based on information determined or generated by using adata analysis algorithm or a machine learning algorithm. The processor180 may control the components of the AI device 100 to execute thedetermined operation.

To this end, the processor 180 may request, search, receive, or utilizedata of the learning processor 130 or the memory 170. The processor 180may control the components of the AI device 100 to execute the predictedoperation or the operation determined to be desirable among the at leastone executable operation.

When the connection of an external device is required to perform thedetermined operation, the processor 180 may generate a control signalfor controlling the external device and may transmit the generatedcontrol signal to the external device.

The processor 180 may acquire intention information for the user inputand may determine the user's requirements based on the acquiredintention information.

The processor 180 may acquire the intention information corresponding tothe user input by using at least one of a speech to text (STT) enginefor converting speech input into a text string or a natural languageprocessing (NLP) engine for acquiring intention information of a naturallanguage.

At least one of the STT engine or the NLP engine may be configured as anartificial neural network, at least part of which is learned accordingto the machine learning algorithm. At least one of the STT engine or theNLP engine may be learned by the learning processor 130, may be learnedby the learning processor 240 of the AI server 200, or may be learned bytheir distributed processing.

The processor 180 may collect history information including theoperation contents of the AI apparatus 100 or the user's feedback on theoperation and may store the collected history information in the memory170 or the learning processor 130 or transmit the collected historyinformation to the external device such as the AI server 200. Thecollected history information may be used to update the learning model.

The processor 180 may control at least part of the components of AIdevice 100 so as to drive an application program stored in memory 170.Furthermore, the processor 180 may operate two or more of the componentsincluded in the AI device 100 in combination so as to drive theapplication program.

FIG. 2 illustrates an AI server 200 according to an embodiment of thepresent disclosure.

Referring to FIG. 2, the AI server 200 may refer to a device that learnsan artificial neural network by using a machine learning algorithm oruses a learned artificial neural network. The AI server 200 may includea plurality of servers to perform distributed processing, or may bedefined as a 5G network. At this time, the AI server 200 may be includedas a partial configuration of the AI device 100, and may perform atleast part of the AI processing together.

The AI server 200 may include a communication unit 210, a memory 230, alearning processor 240, a processor 260, and the like.

The communication unit 210 can transmit and receive data to and from anexternal device such as the AI device 100.

The memory 230 may include a model storage unit 231. The model storageunit 231 may store a learning or learned model (or an artificial neuralnetwork 231 a) through the learning processor 240.

The learning processor 240 may learn the artificial neural network 231 aby using the learning data. The learning model may be used in a state ofbeing mounted on the AI server 200 of the artificial neural network, ormay be used in a state of being mounted on an external device such asthe AI device 100.

The learning model may be implemented in hardware, software, or acombination of hardware and software. If all or part of the learningmodels are implemented in software, one or more instructions thatconstitute the learning model may be stored in memory 230.

The processor 260 may infer the result value for new input data by usingthe learning model and may generate a response or a control commandbased on the inferred result value.

FIG. 3 illustrates an AI system 1 according to an embodiment of thepresent disclosure.

Referring to FIG. 3, in the AI system 1, at least one of an AI server200, a robot 100 a, a self-driving vehicle 100 b, an XR device 100 c, asmartphone 100 d, or a home appliance 100 e is connected to a cloudnetwork 10. The robot 100 a, the self-driving vehicle 100 b, the XRdevice 100 c, the smartphone 100 d, or the home appliance 100 e, towhich the AI technology is applied, may be referred to as AI devices 100a to 100 e.

The cloud network 10 may refer to a network that forms part of a cloudcomputing infrastructure or exists in a cloud computing infrastructure.The cloud network 10 may be configured by using a 3G network, a 4G orLTE network, or a 5G network.

That is, the devices 100 a to 100 e and 200 configuring the AI system 1may be connected to each other through the cloud network 10. Inparticular, each of the devices 100 a to 100 e and 200 may communicatewith each other through a base station, but may directly communicatewith each other without using a base station.

The AI server 200 may include a server that performs AI processing and aserver that performs operations on big data.

The AI server 200 may be connected to at least one of the AI devicesconstituting the AI system 1, that is, the robot 100 a, the self-drivingvehicle 100 b, the XR device 100 c, the smartphone 100 d, or the homeappliance 100 e through the cloud network 10, and may assist at leastpart of AI processing of the connected AI devices 100 a to 100 e.

At this time, the AI server 200 may learn the artificial neural networkaccording to the machine learning algorithm instead of the AI devices100 a to 100 e, and may directly store the learning model or transmitthe learning model to the AI devices 100 a to 100 e.

At this time, the AI server 200 may receive input data from the AIdevices 100 a to 100 e, may infer the result value for the receivedinput data by using the learning model, may generate a response or acontrol command based on the inferred result value, and may transmit theresponse or the control command to the AI devices 100 a to 100 e.

Alternatively, the AI devices 100 a to 100 e may infer the result valuefor the input data by directly using the learning model, and maygenerate the response or the control command based on the inferenceresult.

Hereinafter, various embodiments of the AI devices 100 a to 100 e towhich the above-described technology is applied will be described. TheAI devices 100 a to 100 e illustrated in FIG. 3 may be regarded as aspecific embodiment of the AI device 100 illustrated in FIG. 1.

<AI+Robot>

The robot 100 a, to which the AI technology is applied, may beimplemented as a guide robot, a carrying robot, a cleaning robot, awearable robot, an entertainment robot, a pet robot, an unmanned flyingrobot, or the like.

The robot 100 a may include a robot control module for controlling theoperation, and the robot control module may refer to a software moduleor a chip implementing the software module by hardware.

The robot 100 a may acquire state information about the robot 100 a byusing sensor information acquired from various kinds of sensors, maydetect (recognize) surrounding environment and objects, may generate mapdata, may determine the route and the travel plan, may determine theresponse to user interaction, or may determine the operation.

The robot 100 a may use the sensor information acquired from at leastone sensor among the lidar, the radar, and the camera so as to determinethe travel route and the travel plan.

The robot 100 a may perform the above-described operations by using thelearning model composed of at least one artificial neural network. Forexample, the robot 100 a may recognize the surrounding environment andthe objects by using the learning model, and may determine the operationby using the recognized surrounding information or object information.The learning model may be learned directly from the robot 100 a or maybe learned from an external device such as the AI server 200.

At this time, the robot 100 a may perform the operation by generatingthe result by directly using the learning model, but the sensorinformation may be transmitted to the external device such as the AIserver 200 and the generated result may be received to perform theoperation.

The robot 100 a may use at least one of the map data, the objectinformation detected from the sensor information, or the objectinformation acquired from the external apparatus to determine the travelroute and the travel plan, and may control the driving unit such thatthe robot 100 a travels along the determined travel route and travelplan.

The map data may include object identification information about variousobjects arranged in the space in which the robot 100 a moves. Forexample, the map data may include object identification informationabout fixed objects such as walls and doors and movable objects such aspollen and desks. The object identification information may include aname, a type, a distance, and a position.

In addition, the robot 100 a may perform the operation or travel bycontrolling the driving unit based on the control/interaction of theuser. At this time, the robot 100 a may acquire the intentioninformation of the interaction due to the user's operation or speechutterance, and may determine the response based on the acquiredintention information, and may perform the operation.

<AI+Self-Driving>

The self-driving vehicle 100 b, to which the AI technology is applied,may be implemented as a mobile robot, a vehicle, an unmanned flyingvehicle, or the like.

The self-driving vehicle 100 b may include a self-driving control modulefor controlling a self-driving function, and the self-driving controlmodule may refer to a software module or a chip implementing thesoftware module by hardware. The self-driving control module may beincluded in the self-driving vehicle 100 b as a component thereof, butmay be implemented with separate hardware and connected to the outsideof the self-driving vehicle 100 b.

The self-driving vehicle 100 b may acquire state information about theself-driving vehicle 100 b by using sensor information acquired fromvarious kinds of sensors, may detect (recognize) surrounding environmentand objects, may generate map data, may determine the route and thetravel plan, or may determine the operation.

Like the robot 100 a, the self-driving vehicle 100 b may use the sensorinformation acquired from at least one sensor among the lidar, theradar, and the camera so as to determine the travel route and the travelplan.

In particular, the self-driving vehicle 100 b may recognize theenvironment or objects for an area covered by a field of view or an areaover a certain distance by receiving the sensor information fromexternal devices, or may receive directly recognized information fromthe external devices.

The self-driving vehicle 100 b may perform the above-describedoperations by using the learning model composed of at least oneartificial neural network. For example, the self-driving vehicle 100 bmay recognize the surrounding environment and the objects by using thelearning model, and may determine the traveling movement line by usingthe recognized surrounding information or object information. Thelearning model may be learned directly from the self-driving vehicle 100a or may be learned from an external device such as the AI server 200.

At this time, the self-driving vehicle 100 b may perform the operationby generating the result by directly using the learning model, but thesensor information may be transmitted to the external device such as theAI server 200 and the generated result may be received to perform theoperation.

The self-driving vehicle 100 b may use at least one of the map data, theobject information detected from the sensor information, or the objectinformation acquired from the external apparatus to determine the travelroute and the travel plan, and may control the driving unit such thatthe self-driving vehicle 100 b travels along the determined travel routeand travel plan.

The map data may include object identification information about variousobjects arranged in the space (for example, road) in which theself-driving vehicle 100 b travels. For example, the map data mayinclude object identification information about fixed objects such asstreet lamps, rocks, and buildings and movable objects such as vehiclesand pedestrians. The object identification information may include aname, a type, a distance, and a position.

In addition, the self-driving vehicle 100 b may perform the operation ortravel by controlling the driving unit based on the control/interactionof the user. At this time, the self-driving vehicle 100 b may acquirethe intention information of the interaction due to the user's operationor speech utterance, and may determine the response based on theacquired intention information, and may perform the operation.

<AI+XR>

The XR device 100 c, to which the AI technology is applied, may beimplemented by a head-mount display (HIVID), a head-up display (HUD)provided in the vehicle, a television, a mobile phone, a smartphone, acomputer, a wearable device, a home appliance, a digital signage, avehicle, a fixed robot, a mobile robot, or the like.

The XR device 100 c may analyzes three-dimensional point cloud data orimage data acquired from various sensors or the external devices,generate position data and attribute data for the three-dimensionalpoints, acquire information about the surrounding space or the realobject, and render to output the XR object to be output. For example,the XR device 100 c may output an XR object including the additionalinformation about the recognized object in correspondence to therecognized object.

The XR device 100 c may perform the above-described operations by usingthe learning model composed of at least one artificial neural network.For example, the XR device 100 c may recognize the real object from thethree-dimensional point cloud data or the image data by using thelearning model, and may provide information corresponding to therecognized real object. The learning model may be directly learned fromthe XR device 100 c, or may be learned from the external device such asthe AI server 200.

At this time, the XR device 100 c may perform the operation bygenerating the result by directly using the learning model, but thesensor information may be transmitted to the external device such as theAI server 200 and the generated result may be received to perform theoperation.

<AI+Robot+Self-Driving>

The robot 100 a, to which the AI technology and the self-drivingtechnology are applied, may be implemented as a guide robot, a carryingrobot, a cleaning robot, a wearable robot, an entertainment robot, a petrobot, an unmanned flying robot, or the like.

The robot 100 a, to which the AI technology and the self-drivingtechnology are applied, may refer to the robot itself having theself-driving function or the robot 100 a interacting with theself-driving vehicle 100 b.

The robot 100 a having the self-driving function may collectively referto a device that moves for itself along the given movement line withoutthe user's control or moves for itself by determining the movement lineby itself.

The robot 100 a and the self-driving vehicle 100 b having theself-driving function may use a common sensing method so as to determineat least one of the travel route or the travel plan. For example, therobot 100 a and the self-driving vehicle 100 b having the self-drivingfunction may determine at least one of the travel route or the travelplan by using the information sensed through the lidar, the radar, andthe camera.

The robot 100 a that interacts with the self-driving vehicle 100 bexists separately from the self-driving vehicle 100 b and may performoperations interworking with the self-driving function of theself-driving vehicle 100 b or interworking with the user who rides onthe self-driving vehicle 100 b.

At this time, the robot 100 a interacting with the self-driving vehicle100 b may control or assist the self-driving function of theself-driving vehicle 100 b by acquiring sensor information on behalf ofthe self-driving vehicle 100 b and providing the sensor information tothe self-driving vehicle 100 b, or by acquiring sensor information,generating environment information or object information, and providingthe information to the self-driving vehicle 100 b.

Alternatively, the robot 100 a interacting with the self-driving vehicle100 b may monitor the user boarding the self-driving vehicle 100 b, ormay control the function of the self-driving vehicle 100 b through theinteraction with the user. For example, when it is determined that thedriver is in a drowsy state, the robot 100 a may activate theself-driving function of the self-driving vehicle 100 b or assist thecontrol of the driving unit of the self-driving vehicle 100 b. Thefunction of the self-driving vehicle 100 b controlled by the robot 100 amay include not only the self-driving function but also the functionprovided by the navigation system or the audio system provided in theself-driving vehicle 100 b.

Alternatively, the robot 100 a that interacts with the self-drivingvehicle 100 b may provide information or assist the function to theself-driving vehicle 100 b outside the self-driving vehicle 100 b. Forexample, the robot 100 a may provide traffic information includingsignal information and the like, such as a smart signal, to theself-driving vehicle 100 b, and automatically connect an electriccharger to a charging port by interacting with the self-driving vehicle100 b like an automatic electric charger of an electric vehicle.

<AI+Robot+XR>

The robot 100 a, to which the AI technology and the XR technology areapplied, may be implemented as a guide robot, a carrying robot, acleaning robot, a wearable robot, an entertainment robot, a pet robot,an unmanned flying robot, a drone, or the like.

The robot 100 a, to which the XR technology is applied, may refer to arobot that is subjected to control/interaction in an XR image. In thiscase, the robot 100 a may be separated from the XR device 100 c andinterwork with each other.

When the robot 100 a, which is subjected to control/interaction in theXR image, may acquire the sensor information from the sensors includingthe camera, the robot 100 a or the XR device 100 c may generate the XRimage based on the sensor information, and the XR device 100 c mayoutput the generated XR image. The robot 100 a may operate based on thecontrol signal input through the XR device 100 c or the user'sinteraction.

For example, the user can confirm the XR image corresponding to the timepoint of the robot 100 a interworking remotely through the externaldevice such as the XR device 100 c, adjust the self-driving travel pathof the robot 100 a through interaction, control the operation ordriving, or confirm the information about the surrounding object.

<AI+Self-Driving+XR>

The self-driving vehicle 100 b, to which the AI technology and the XRtechnology are applied, may be implemented as a mobile robot, a vehicle,an unmanned flying vehicle, or the like.

The self-driving driving vehicle 100 b, to which the XR technology isapplied, may refer to a self-driving vehicle having a means forproviding an XR image or a self-driving vehicle that is subjected tocontrol/interaction in an XR image. Particularly, the self-drivingvehicle 100 b that is subjected to control/interaction in the XR imagemay be distinguished from the XR device 100 c and interwork with eachother.

The self-driving vehicle 100 b having the means for providing the XRimage may acquire the sensor information from the sensors including thecamera and output the generated XR image based on the acquired sensorinformation. For example, the self-driving vehicle 100 b may include anHUD to output an XR image, thereby providing a passenger with a realobject or an XR object corresponding to an object in the screen.

At this time, when the XR object is output to the HUD, at least part ofthe XR object may be outputted so as to overlap the actual object towhich the passenger's gaze is directed. Meanwhile, when the XR object isoutput to the display provided in the self-driving vehicle 100 b, atleast part of the XR object may be output so as to overlap the object inthe screen. For example, the self-driving vehicle 100 b may output XRobjects corresponding to objects such as a lane, another vehicle, atraffic light, a traffic sign, a two-wheeled vehicle, a pedestrian, abuilding, and the like.

When the self-driving vehicle 100 b, which is subjected tocontrol/interaction in the XR image, may acquire the sensor informationfrom the sensors including the camera, the self-driving vehicle 100 b orthe XR device 100 c may generate the XR image based on the sensorinformation, and the XR device 100 c may output the generated XR image.The self-driving vehicle 100 b may operate based on the control signalinput through the external device such as the XR device 100 c or theuser's interaction.

SUMMARY

An object of the present disclosure is to provide a method of a methodof transmitting and receiving a downlink signal between a user equipmentand a base station in a wireless communication system, and an apparatusfor supporting the same.

The technical objects that can be achieved through the presentdisclosure are not limited to what has been particularly describedhereinabove and other technical objects not described herein will bemore clearly understood by persons skilled in the art from the followingdetailed description.

The present disclosure provides a method of transmitting and receiving adownlink signal between a user equipment and a base station in awireless communication system, and an apparatus for supporting the same.

According to an aspect of the present disclosure, provided herein is amethod of receiving a downlink signal by a user equipment (UE) in awireless communication system, including receiving downlink controlinformation (DCI) for scheduling one or more physical downlink sharedchannels (PDSCHs); assuming that a second PDSCH scheduled for the UE ispresent so as to overlap with a first PDSCH scheduled by the DCI on atime resource, based on a plurality of transmission configurationindication (TCI) states related to one reference resource (RS) set, theplurality of TCI states being allocated to the UE by the DCI; andreceiving the first PDSCH based on one of RS sets related to (i) theassumption and (ii) the plurality of TCI states.

The method of receiving a downlink signal may further include receivingthe second PDSCH, The second PDSCH may be scheduled by the DCI oranother DCI.

Based on the first PDSCH and the second PDSCH overlapping on a frequencyresource as well as on the time resource, the UE may differentlyconfigure a first reception beam for the first PDSCH and a secondreception beam for the second PDSCH to receive the first PDSCH and thesecond PDSCH.

The one RS set for receiving the first PDSCH may be determined asfollows, based on determination that (i) the RS sets related to theplurality of TCI states correspond to two RS sets and (ii) one or moredemodulation reference signal (DMRS) ports indicated by the DCI areincluded in different code division multiplexing (CDM) groups.

-   -   The one RS set for receiving the first PDSCH may be determined        as a first RS set of the two RS sets, based on one or more DMRS        ports related to the first PDSCH, included in a first CDM group.    -   The one RS set for receiving the first PDSCH is determined as a        second RS set of the two RS sets, based on one or more DMRS        ports related to the first PDSCH, included in a second CDM        group.

The UE may receive the second PDSCH scheduled by the DCI. The secondPDSCH may be received based on an RS set different from the one RS setfor receiving the first PDSCH among the two RS sets.

The first CDM group and the second CDM group may be configured asfollows, based on a first DMRS configuration type configured for the UE.

-   -   The first CDM group may include DMRS port #0, DMRS port #1, DMRS        port #4, and DMRS port #5.    -   The second CDM group may include DMRS port #2, DMRS port #3,        DMRS port #6, and DMRS port #7.

The first CDM group and the second CDM group may be configured asfollows, based on a second DMRS configuration type configured for theUE.

-   -   The first CDM group may include DMRS port #0, DMRS port #1, DMRS        port #6, and DMRS port #7    -   The second CDM group may include DMRS port #2, DMRS port #3,        DMRS port #4, DMRS port #5, DMRS port #8, DMRS port #9, DMRS        port #10, and DMRS port #11.

Based on determination that (i) the RS sets related to the plurality ofTCI states correspond to two RS sets and (ii) one or more demodulationreference signal (DMRS) ports indicated by the DCI are included in onecode division multiplexing (CDM) group, the one RS set for receiving thefirst PDSCH may be determined as one specific RS set of the two RS sets,without considering the one CDM group.

The one specific RS set for receiving the first PDSCH may be determinedas a first RS set or a second RS set among the two RS sets.

Based on determination that (i) the RS sets related to the plurality ofTCI states correspond to two RS sets and (ii) one or more demodulationreference signal (DMRS) ports indicated by the DCI are included in onecode division multiplexing (CDM) group, the one RS set for receiving thefirst PDSCH may be determined as a first RS set or a second RS set ofthe two RS sets, based on one CDM group corresponding to a first CDMgroup or a second CDM group.

The one RS set for receiving the first PDSCH may be determined asfollows according to whether the one CDM group to which the one or moreDMRS ports indicated by the DCI is included in the first CDM group orthe second CDM group.

-   -   The one RS set for receiving the first PDSCH may be determined        as the first RS set of the two RS sets based on the one CDM        group corresponding to the first CDM group.    -   The one RS set for receiving the first PDSCH may be determined        as the second RS set of the two RS sets based on the one CDM        group corresponding to the second CDM group.

The UE may receive the first PDSCH using a first reception beam for thefirst PDSCH determined based on the one RS set.

Overlapping of the first PDSCH and the second PDSCH on the time resourcemay include scheduling of the first PDSCH and the second PDSCH in atleast one or more identical symbols.

In another aspect of the present disclosure, provided herein is a userequipment (UE) for receiving a downlink signal in a wirelesscommunication system, including at least one receiver; at least oneprocessor; and at least one memory operably connected to the at leastone processor, for storing instructions for causing the at least oneprocessor to perform a specific operation when the at least oneprocessor is executed. The specific operation includes: receivingdownlink control information (DCI) for scheduling one or more physicaldownlink shared channels (PDSCHs); assuming that a second PDSCHscheduled for the UE is present so as to overlap with a first PDSCHscheduled by the DCI on a time resource, based on a plurality oftransmission configuration indication (TCI) states related to onereference resource (RS) set, the plurality of TCI states being allocatedto the UE by the DCI; and receiving the first PDSCH based on one of RSsets related to (i) the assumption and (ii) the plurality of TCI states.

The UE may communicate with at least one of a mobile terminal, anetwork, or a self-driving vehicle other than a vehicle in which the UEis included.

In another aspect of the present disclosure, provided herein is a basestation (BS) for transmitting a downlink signal in a wirelesscommunication system, including at least one transmitter; at least oneprocessor; and at least one memory operably connected to the at leastone processor, for storing instructions for causing the at least oneprocessor to perform a specific operation when the at least oneprocessor is executed. The specific operation includes: transmittingdownlink control information (DCI) for scheduling one or more physicaldownlink shared channels (PDSCHs) to a user equipment (UE), wherein afirst PDSCH scheduled by the DCI overlaps with a second PDSCH scheduledfor the UE by the DCI or another DCI on a time resource; andtransmitting the first PDSCH and the second PDSCH to the UE.

It is to be understood that both the foregoing general description andthe following detailed description of the present disclosure areexemplary and explanatory and are intended to provide furtherexplanation of the disclosure as claimed.

As is apparent from the above description, the embodiments of thepresent disclosure have the following effects.

According to the present disclosure, even when a UE misses one of pluralDCIs that schedule respective PDSCHs, the UE may recognize that a PDSCHscheduled by the missed DCI is present.

As a specific example, the UE may recognize whether plural PDSCHs aresimultaneously scheduled for the UE during a predetermined timeduration, based on the number of TCI states allocated (or scheduled) byat least one DCI. Therefore, the UE may raise the reliability of PDSCHreception through a reception method of minimizing interference betweenPDSCHs (e.g., respective reception filters are configured or differentreception beams are defined).

It will be appreciated by persons skilled in the art that that theeffects that can be achieved through the embodiments of the presentdisclosure are not limited to those described above and otheradvantageous effects of the present disclosure will be more clearlyunderstood from the following detailed description. That is, unintendedeffects according to implementation of the present disclosure may bederived by those skilled in the art from the embodiments of the presentdisclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the disclosure, provide embodiments of the presentdisclosure together with detail explanation. Yet, a technicalcharacteristic of the present disclosure is not limited to a specificdrawing. Characteristics disclosed in each of the drawings are combinedwith each other to configure a new embodiment. Reference numerals ineach drawing correspond to structural elements.

FIG. 1 illustrates an AI device according to an embodiment of thepresent disclosure.

FIG. 2 illustrates an AI server according to an embodiment of thepresent disclosure.

FIG. 3 illustrates an AI system according to an embodiment of thepresent disclosure.

FIG. 4 is a diagram illustrating physical channels and a general signaltransmission method using the physical channels.

FIG. 5 is a diagram illustrating a radio frame structure in an NR systemto which embodiments of the present disclosure are applicable.

FIG. 6 is a diagram illustrating a slot structure in an NR system towhich embodiments of the present disclosure are applicable.

FIG. 7 is a diagram illustrating a self-contained slot structure in anNR system to which embodiments of the present disclosure are applicable.

FIG. 8 is a diagram illustrating the structure of one REG in an NRsystem to which embodiments of the present disclosure are applicable.

FIGS. 9 and 10 are diagrams illustrating representative methods forconnecting TXRUs to antenna elements.

FIG. 11 is a diagram schematically illustrating an exemplary hybrid BFstructure from the perspective of TXRUs and physical antennas accordingto the present disclosure.

FIG. 12 is a diagram schematically illustrating an exemplary beamsweeping operation for a synchronization signal and system informationin a DL transmission procedure according to the present disclosure.

FIGS. 13A and 13B are diagrams schematically illustrating an example ofa front loaded DMRS of a first DMRS configuration type applicable to thepresent disclosure.

FIG. 14 is a diagram illustrating cases in which two PDSCHs overlap ontime and/or frequency resources, which are applicable to the presentdisclosure.

FIGS. 15A and 15B are diagrams illustrating a signal transmission andreception operation between a UE and a BS (or a network) applicable tothe present disclosure.

FIG. 16 is a diagram illustrating operations of a UE and a BS applicableto the present disclosure, FIG. 17 is a flowchart illustrating anoperation of a UE according to the present disclosure, and FIG. 18 is aflowchart illustrating an operation of a BS according to the presentdisclosure.

FIG. 19 is a diagram illustrating configurations of a UE and a BS bywhich proposed embodiments can be implemented.

FIG. 20 is a block diagram of a communication device by which proposedembodiments can be implemented.

DETAILED DESCRIPTION

The embodiments of the present disclosure described below arecombinations of elements and features of the present disclosure inspecific forms. The elements or features may be considered selectiveunless otherwise mentioned. Each element or feature may be practicedwithout being combined with other elements or features. Further, anembodiment of the present disclosure may be constructed by combiningparts of the elements and/or features. Operation orders described inembodiments of the present disclosure may be rearranged. Someconstructions or elements of any one embodiment may be included inanother embodiment and may be replaced with corresponding constructionsor features of another embodiment.

In the description of the attached drawings, a detailed description ofknown procedures or steps of the present disclosure will be avoided lestit should obscure the subject matter of the present disclosure. Inaddition, procedures or steps that could be understood to those skilledin the art will not be described either.

Throughout the specification, when a certain portion “includes” or“comprises” a certain component, this indicates that other componentsare not excluded and may be further included unless otherwise noted. Theterms “unit”, “-or/er” and “module” described in the specificationindicate a unit for processing at least one function or operation, whichmay be implemented by hardware, software or a combination thereof. Inaddition, the terms “a or an”, “one”, “the” etc. may include a singularrepresentation and a plural representation in the context of the presentdisclosure (more particularly, in the context of the following claims)unless indicated otherwise in the specification or unless contextclearly indicates otherwise.

In the embodiments of the present disclosure, a description is mainlymade of a data transmission and reception relationship between a BaseStation (BS) and a User Equipment (UE). A BS refers to a UE node of anetwork, which directly communicates with a UE. A specific operationdescribed as being performed by the BS may be performed by an upper nodeof the BS.

Namely, it is apparent that, in a network comprised of a plurality ofnetwork nodes including a BS, various operations performed forcommunication with a UE may be performed by the BS, or network nodesother than the BS. The term ‘BS’ may be replaced with a fixed station, aNode B, an evolved Node B (eNode B or eNB), gNode B (gNB), an AdvancedBase Station (ABS), an access point, etc.

In the embodiments of the present disclosure, the term UE may bereplaced with a UE, a Mobile Station (MS), a Subscriber Station (SS), aMobile Subscriber Station (MSS), a mobile UE, an Advanced Mobile Station(AMS), etc.

A transmission end is a fixed and/or mobile node that provides a dataservice or a voice service and a reception end is a fixed and/or mobilenode that receives a data service or a voice service. Therefore, a UEmay serve as a transmission end and a BS may serve as a reception end,on an UpLink (UL). Likewise, the UE may serve as a reception end and theBS may serve as a transmission end, on a DownLink (DL).

The embodiments of the present disclosure may be supported by standardspecifications disclosed for at least one of wireless access systemsincluding an Institute of Electrical and Electronics Engineers (IEEE)802.xx system, a 3rd Generation Partnership Project (3GPP) system, a3GPP Long Term Evolution (LTE) system, 3GPP 5G NR system and a 3GPP2system. In particular, the embodiments of the present disclosure may besupported by the standard specifications, 3GPP TS 38.211, 3GPP TS38.212, 3GPP TS 38.213, 3GPP TS 38.321 and 3GPP TS 38.331. That is, thesteps or parts, which are not described to clearly reveal the technicalidea of the present disclosure, in the embodiments of the presentdisclosure may be explained by the above standard specifications. Allterms used in the embodiments of the present disclosure may be explainedby the standard specifications.

Reference will now be made in detail to the embodiments of the presentdisclosure with reference to the accompanying drawings. The detaileddescription, which will be given below with reference to theaccompanying drawings, is intended to explain exemplary embodiments ofthe present disclosure, rather than to show the only embodiments thatcan be implemented according to the disclosure.

The following detailed description includes specific terms in order toprovide a thorough understanding of the present disclosure. However, itwill be apparent to those skilled in the art that the specific terms maybe replaced with other terms without departing the technical spirit andscope of the present disclosure.

Hereinafter, 3GPP NR system is explained, which are examples of wirelessaccess systems.

Technology described below may be applied to various wireless accesssystems such as code division multiple access (CDMA), frequency divisionmultiple access (FDMA), time division multiple access (TDMA), orthogonalfrequency division multiple access (OFDMA), and single carrier frequencydivision multiple access (SC-FDMA).

To clarify technical features of the present disclosure, embodiments ofthe present disclosure are described focusing upon a 3GPP NR system.However, the embodiments proposed in the present disclosure may beequally applied to other wireless systems (e.g., 3GPP LTE, IEEE 802.16,and IEEE 802.11).

1. NR System

1.1. Physical Channels and General Signal Transmission

In a wireless access system, a UE receives information from a basestation on a DL and transmits information to the base station on a UL.The information transmitted and received between the UE and the basestation includes general data information and various types of controlinformation. There are many physical channels according to thetypes/usages of information transmitted and received between the basestation and the UE.

FIG. 4 illustrates physical channels and a general signal transmissionmethod using the physical channels, which may be used in embodiments ofthe present disclosure.

A UE performs initial cell search such as synchronization establishmentwith a BS in step S11 when the UE is powered on or enters a new cell. Tothis end, the UE may receive a primary synchronization channel (P-SCH)and a secondary synchronization channel (S-SCH) from the BS, establishsynchronization with the BS, and acquire information such as a cellidentity (ID).

Thereafter, the UE may receive a physical broadcast channel (PBCH) fromthe BS to acquire broadcast information in the cell.

Meanwhile, the UE may receive a DL reference signal (RS) in the initialcell search step to confirm a DL channel state.

Upon completion of initial cell search, the UE may receive a physicaldownlink control channel (PDCCH) and a physical downlink shared channel(PDSCH) according to information included in the PDCCH to acquire moredetailed system information in step S12.

Next, the UE may perform a random access procedure such as steps S13 toS16 to complete access to the BS. To this end, the UE may transmit apreamble through a physical random access channel (PRACH) (S13) andreceive a random access response (RAR) to the preamble through the PDCCHand the PDSCH corresponding to the PDCCH (S14). The UE may transmit aphysical uplink shared channel (PUSCH). In the case of contention-basedrandom access, a contention resolution procedure including transmissionof a PRACH signal (S15) and reception of a PDCCH signal and a PDSCHsignal corresponding to the PDCCH signal (S16) may be additionallyperformed.

The UE which has performed the above procedures may receive a PDCCHsignal and/or a PDSCH signal (S17) and transmit a PUSCH signal and/or aphysical uplink control channel (PUCCH) signal (S18) as a general UL/DLsignal transmission procedure.

Control information that the UE transmits to the BS is referred to asuplink control information (UCI). The UCI includes a hybrid automaticrepeat and request (HARD) acknowledgement (ACK)/negative ACK (NACK)signal, a scheduling request (SR), a channel quality indicator (CQI), aprecoding matrix index (PMI), a rank indicator (RI), or beam indication(BI) information.

In an NR system, the UCI is generally periodically transmitted on thePUCCH. However, according to an embodiment (if control information andtraffic data should be transmitted simultaneously), the controlinformation and traffic data may be transmitted on the PUSCH. Inaddition, the UCI may be transmitted aperiodically on the PUSCH, uponreceipt of a request/command from a network.

1.2. Radio Frame Structure

FIG. 5 is a diagram illustrating a radio frame structure in an NR systemto which embodiments of the present disclosure are applicable.

In the NR system, UL and DL transmissions are based on a frame asillustrated in FIG. 5. One radio frame is 10 ms in duration, defined bytwo 5-ms half-frames. One half-frame is defined by five 1-ms subframes.One subframe is divided into one or more slots, and the number of slotsin a subframe depends on an SCS. Each slot includes 12 or 14 OFDM(A)symbols according to a CP. Each slot includes 14 symbols in a normal CPcase, and 12 symbols in an extended CP case. Herein, a symbol mayinclude an OFDM symbol (or a CP-OFDM) symbol and an SC-FDMA symbol (or aDFT-s-OFDM symbol).

Table 1 lists the number of symbols per slot, the number of slots perframe, and the number of slots per subframe in the normal CP case, andTable 2 lists the number of symbols per slot, the number of slots perframe, and the number of slots per subframe in the extended CP case.

TABLE 1 μ N_(symb) ^(slot) N_(slot) ^(frame, μ) N_(slot) ^(subframe, μ)0 14 10 1 1 14 20 2 2 14 40 4 3 14 80 8 4 14 160 16 5 14 320 32

TABLE 2 μ N_(symb) ^(slot) N_(symb) ^(frame, μ) N_(slot) ^(subframe, μ)2 12 40 4

In the above tables, N^(slot) _(symb) represents the number of symbolsin a slot, N^(frame,d) _(slot) represents the number of slots in aframe, and N^(subframe) _(slot) represents the number of slots in asubframe.

In the NR system to which the present disclosure is applicable,different OFDM(A) numerologies (e.g., SCSs, CP length, and so on) may beconfigured for a plurality of cells aggregated for a UE. Therefore, the(absolute) duration of a time resource (e.g., an SF, slot, or TTI) (forthe convenience of description, generically referred to as a time unit(TU)) including the same number of symbols may be different between theaggregated cells.

FIG. 6 is a diagram illustrating a slot structure in an NR system towhich embodiments of the present disclosure are applicable.

One slot includes a plurality of symbols in the time domain. Forexample, one slot includes 7 symbols in a normal CP case and 6 symbolsin an extended CP case.

A carrier includes a plurality of subcarriers in the frequency domain.An RB is defined by a plurality of (e.g., 12) consecutive subcarriers inthe frequency domain.

A bandwidth part (BWP), which is defined by a plurality of consecutive(P)RBs in the frequency domain, may correspond to one numerology (e.g.,SCS, CP length, and so on).

A carrier may include up to N (e.g., 5) BWPs. Data communication may beconducted in an activated BWP, and only one BWP may be activated for oneUE. In a resource grid, each element is referred to as an RE, to whichone complex symbol may be mapped.

FIG. 7 is a diagram illustrating a self-contained slot structures in anNR system to which embodiments of the present disclosure are applicable.

In FIG. 7, the hatched area (e.g., symbol index=0) indicates a DLcontrol region, and the black area (e.g., symbol index=13) indicates aUL control region. The remaining area (e.g., symbol index=1 to 12) maybe used for DL or UL data transmission.

Based on this structure, a base station and a UE may sequentiallyperform DL transmission and UL transmission in one slot. That is, thebase station and UE may transmit and receive not only DL data but also aUL ACK/NACK for the DL data in one slot. Consequently, this structuremay reduce a time required until data retransmission when a datatransmission error occurs, thereby minimizing the latency of a finaldata transmission.

In this self-contained slot structure, a predetermined length of timegap is required to allow the base station and UE to switch fromtransmission mode to reception mode and vice versa. To this end, in theself-contained slot structure, some OFDM symbols at the time ofswitching from DL to UL may be configured as a guard period (GP).

Although it has been described above that the self-contained slotstructure includes both DL and UL control regions, these control regionsmay be selectively included in the self-contained slot structure. Inother words, the self-contained slot structure according to the presentdisclosure may include either the DL control region or the UL controlregion as well as both the DL and UL control regions as illustrated inFIG. 8.

Further, the order of the regions in one slot may vary according toembodiments. For example, one slot may be configured in the order of DLcontrol region, DL data region, UL control region, and UL data region,or UL control region, UL data region, DL control region, and DL dataregion.

A PDCCH may be transmitted in the DL control region, and a PDSCH may betransmitted in the DL data region. A PUCCH may be transmitted in the ULcontrol region, and a PUSCH may be transmitted in the UL data region.

The PDCCH may deliver downlink control information (DCI), for example,DL data scheduling information, UL data scheduling information, and soon. The PUCCH may deliver uplink control information (UCI), for example,an ACK/NACK for DL data, channel state information (CSI), a schedulingrequest (SR), and so on.

The PDSCH conveys DL data (e.g., DL-shared channel transport block(DL-SCH TB)) and uses a modulation scheme such as quadrature phase shiftkeying (QPSK), 16-ary quadrature amplitude modulation (16QAM), 64QAM, or256QAM. A TB is encoded into a codeword. The PDSCH may deliver up to twocodewords. Scrambling and modulation mapping are performed on a codewordbasis, and modulation symbols generated from each codeword are mapped toone or more layers (layer mapping). Each layer together with ademodulation reference signal (DMRS) is mapped to resources, generatedas an OFDM symbol signal, and transmitted through a correspondingantenna port.

The PDCCH carries DCI and uses QPSK as a modulation scheme. One PDCCHincludes 1, 2, 4, 8, or 16 control channel elements (CCEs) according toan aggregation level (AL). One CCE includes 6 resource element groups(REGs). One REG is defined by one OFDM symbol by one (P)RB.

FIG. 8 is a diagram illustrating the structure of one REG in an NRsystem to which embodiments of the present disclosure are applicable.

In FIG. 8, D represents an RE to which DCI is mapped, and R representsan RE to which a DMRS is mapped. The DMRS is mapped to REs #1, #5, and#9 along the frequency axis in one symbol.

The PDCCH is transmitted in a control resource set (CORESET). A CORESETis defined as a set of REGs having a given numerology (e.g., SCS, CPlength, and so on). A plurality of CORESETs for one UE may overlap witheach other in the time/frequency domain. A CORESET may be configured bysystem information (e.g., a master information block (MIB)) or byUE-specific higher layer (RRC) signaling. Specifically, the number ofRBs and the number of symbols (up to 3 symbols) included in a CORESETmay be configured by higher-layer signaling.

The PUSCH delivers UL data (e.g., UL-shared channel transport block(UL-SCH TB)) and/or UCI based on a CP-OFDM waveform or a DFT-s-OFDMwaveform. When the PUSCH is transmitted in the DFT-s-OFDM waveform, theUE transmits the PUSCH by transform precoding. For example, whentransform precoding is impossible (e.g., disabled), the UE may transmitthe PUSCH in the CP-OFDM waveform, while when transform precoding ispossible (e.g., enabled), the UE may transmit the PUSC in the CP-OFDM orDFT-s-OFDM waveform. A PUSCH transmission may be dynamically scheduledby a UL grant in DCI, or semi-statically scheduled by higher-layer(e.g., RRC) signaling (and/or layer 1 (L1) signaling such as a PDCCH)(configured grant). The PUSCH transmission may be performed in acodebook-based or non-codebook-based manner.

The PUCCH delivers UCI, an HARQ-ACK, and/or an SR and is classified as ashort PUCCH or a long PUCCH according to the transmission duration ofthe PUCCH. Table 3 lists exemplary PUCCH formats.

TABLE 3 PUCCH Length in OFDM Number of format symbols N_(symb) ^(PUCCH)bits Usage Etc 0 1-2  ≤2 HARQ, SR Sequence selection 1 4-14 ≤2 HARQ,[SR] Sequence modulation 2 1-2  >2 HARQ, CSI, [SR] CP-OFDM 3 4-14 >2HARQ, CSI, [SR] DFT-s-OFDM (no UE multiplexing) 4 4-14 >2 HARQ, CSI,[SR] DFT-s-OFDM (Pre DFT OCC)

PUCCH format 0 conveys UCI of up to 2 bits and is mapped in asequence-based manner, for transmission. Specifically, the UE transmitsspecific UCI to the base station by transmitting one of a plurality ofsequences on a PUCCH of PUCCH format 0. Only when the UE transmits apositive SR, the UE transmits the PUCCH of PUCCH format 0 in a PUCCHresource for a corresponding SR configuration.

PUCCH format 1 conveys UCI of up to 2 bits and modulation symbols of theUCI are spread with an OCC (which is configured differently whetherfrequency hopping is performed) in the time domain. The DMRS istransmitted in a symbol in which a modulation symbol is not transmitted(i.e., transmitted in time division multiplexing (TDM)).

PUCCH format 2 conveys UCI of more than 2 bits and modulation symbols ofthe DCI are transmitted in frequency division multiplexing (FDM) withthe DMRS. The DMRS is located in symbols #1, #4, #7, and #10 of a givenRB with a density of ⅓. A pseudo noise (PN) sequence is used for a DMRSsequence. For 1-symbol PUCCH format 2, frequency hopping may beactivated.

PUCCH format 3does not support UE multiplexing in the same PRBS, andconveys UCI of more than 2 bits. In other words, PUCCH resources ofPUCCH format 3 do not include an OCC. Modulation symbols are transmittedin TDM with the DMRS.

PUCCH format 4 supports multiplexing of up to 4 UEs in the same PRBS,and conveys UCI of more than 2 bits. In other words, PUCCH resources ofPUCCH format 3 includes an OCC. Modulation symbols are transmitted inTDM with the DMRS.

1.3. Analog Beamforming

In a millimeter wave (mmW) system, since a wavelength is short, aplurality of antenna elements can be installed in the same area. Thatis, considering that the wavelength at 30 GHz band is 1 cm, a total of100 antenna elements can be installed in a 5 * 5 cm panel at intervalsof 0.5 lambda (wavelength) in the case of a 2-dimensional array.Therefore, in the mmW system, it is possible to improve the coverage orthroughput by increasing the beamforming (BF) gain using multipleantenna elements.

In this case, each antenna element can include a transceiver unit (TXRU)to enable adjustment of transmit power and phase per antenna element. Bydoing so, each antenna element can perform independent beamforming perfrequency resource.

However, installing TXRUs in all of the about 100 antenna elements isless feasible in terms of cost. Therefore, a method of mapping aplurality of antenna elements to one TXRU and adjusting the direction ofa beam using an analog phase shifter has been considered. However, thismethod is disadvantageous in that frequency selective beamforming isimpossible because only one beam direction is generated over the fullband.

To solve this problem, as an intermediate form of digital BF and analogBF, hybrid BF with B TXRUs that are fewer than Q antenna elements can beconsidered. In the case of the hybrid BF, the number of beam directionsthat can be transmitted at the same time is limited to B or less, whichdepends on how B TXRUs and Q antenna elements are connected.

FIGS. 9 and 10 are diagrams illustrating representative methods forconnecting TXRUs to antenna elements. Here, the TXRU virtualizationmodel represents the relationship between TXRU output signals andantenna element output signals.

FIG. 9 shows a method for connecting TXRUs to sub-arrays. In FIG. 9, oneantenna element is connected to one TXRU.

Meanwhile, FIG. 10 shows a method for connecting all TXRUs to allantenna elements. In FIG. 10, all antenna elements are connected to allTXRUs. In this case, separate addition units are required to connect allantenna elements to all TXRUs as shown in FIG. 10.

In FIGS. 9 and 10, W indicates a phase vector weighted by an analogphase shifter. That is, W is a major parameter determining the directionof the analog beamforming. In this case, the mapping relationshipbetween CSI-RS antenna ports and TXRUs may be 1:1 or 1-to-many.

The configuration shown in FIG. 9 has a disadvantage in that it isdifficult to achieve beamforming focusing but has an advantage in thatall antennas can be configured at low cost.

On the contrary, the configuration shown in FIG. 10 is advantageous inthat beamforming focusing can be easily achieved. However, since allantenna elements are connected to the TXRU, it has a disadvantage ofhigh cost.

When a plurality of antennas is used in the NR system to which thepresent disclosure is applicable, a hybrid beamforming (BF) scheme inwhich digital BF and analog BF are combined may be applied. In thiscase, analog BF (or radio frequency (RF) BF) means an operation ofperforming precoding (or combining) at an RF stage. In hybrid BF, eachof a baseband stage and the RF stage perform precoding (or combining)and, therefore, performance approximating to digital BF can be achievedwhile reducing the number of RF chains and the number of adigital-to-analog (D/A) (or analog-to-digital (A/D) converters.

For convenience of description, a hybrid BF structure may be representedby N transceiver units (TXRUs) and M physical antennas. In this case,digital BF for L data layers to be transmitted by a transmission end maybe represented by an N-by-L matrix. N converted digital signals obtainedthereafter are converted into analog signals via the TXRUs and thensubjected to analog BF, which is represented by an M-by-N matrix.

FIG. 11 is a diagram schematically illustrating an exemplary hybrid BFstructure from the perspective of TXRUs and physical antennas accordingto the present disclosure. In FIG. 11, the number of digital beams is Land the number analog beams is N.

Additionally, in the NR system to which the present disclosure isapplicable, a BS designs analog BF to be changed in units of symbols toprovide more efficient BF support to a UE located in a specific area.Furthermore, as illustrated in FIG. 11, when N specific TXRUs and M RFantennas are defined as one antenna panel, the NR system according tothe present disclosure considers introducing a plurality of antennapanels to which independent hybrid BF is applicable.

In the case in which the BS utilizes a plurality of analog beams asdescribed above, the analog beams advantageous for signal reception maydiffer according to a UE. Therefore, in the NR system to which thepresent disclosure is applicable, a beam sweeping operation is beingconsidered in which the BS transmits signals (at least synchronizationsignals, system information, paging, and the like) by applying differentanalog beams in a specific subframe (SF) or slot on a symbol-by-symbolbasis so that all UEs may have reception opportunities.

FIG. 12 is a diagram schematically illustrating an exemplary beamsweeping operation for a synchronization signal and system informationin a DL transmission procedure according to the present disclosure.

In FIG. 12 below, a physical resource (or physical channel) on which thesystem information of the NR system to which the present disclosure isapplicable is transmitted in a broadcasting manner is referred to as anxPBCH. Here, analog beams belonging to different antenna panels withinone symbol may be simultaneously transmitted.

As illustrated in FIG. 12, in order to measure a channel for each analogbeam in the NR system to which the present disclosure is applicable,introducing a beam RS (BRS), which is a reference signal (RS)transmitted by applying a single analog beam (corresponding to aspecific antenna panel), is being discussed. The BRS may be defined fora plurality of antenna ports and each antenna port of the BRS maycorrespond to a single analog beam. In this case, unlike the BRS, asynchronization signal or the xPBCH may be transmitted by applying allanalog beams in an analog beam group such that any UE may receive thesignal well.

1.4. Demodulation Reference Signal (DMRS)

In the NR system to which the present disclosure is applicable, a DMRSmay be transmitted and received in a front-loaded structure.Alternatively, an additional DMRS may be transmitted and received inaddition to the front-loaded DMRS.

The front-loaded DMRS may support fast decoding. The first OFDM symbolin which the front-loaded DMRS is carried may be determined as the third(e.g., 1=2) or fourth (e.g., 1=3) OFDM symbol. The first OFDM symbolposition may be indicated by a PBCH.

The number of OFDM symbols in which the front-loaded DMRS is occupiedmay be indicated by a combination of DCI and radio resource control(RRC) signaling.

The additional DMRS may be configured for a high-speed UE. Theadditional DMRS may be positioned in the middle/last symbol(s) in aslot. If one front-loaded DMRS is configured, the additional DMRS may beallocated to 0 to 3 OFDM symbols. If two front-loaded DMRS symbols areconfigured, the additional DMRS may be allocated to 0 to 2 OFDM symbols.

The front-loaded DMRS may be divided into two types and one of the twotypes may be indicated through higher layer signaling (e.g., RRCsignaling).

In the present disclosure, two DMRS configuration types may be applied.A DMRS configuration type which is substantially configured for the UEamong the two DMRS configuration types may be indicated by higher layersignaling (e.g., RRC signaling).

DMRS configuration type 1 may be classified as follows according to thenumber of OFDM symbols to which the front-loaded DMRS is allocated.

DMRS configuration type 1 and number of OFDM symbols to which thefront-loaded DMRS is allocated=1

Up to 4 ports (e.g., P0 to P3) may be multiplexed based on length-2frequency code division multiplexing (F-CDM) and frequency divisionmultiplexing (FDM) schemes. RS density may be set to 6 REs per port in aresource block (RB).

DMRS configuration type 1 and number of OFDM symbols to which thefront-loaded DMRS is allocated=2

Up to 8 ports (e.g., P0 to P7) may be multiplexed based on length-2F-CDM, length-2 time CDM (T-CDM), and FDM schemes. If presence of aPT-RS is configured by higher layer signaling, T-CDM may be fixed to [11]. RS density may be set to 12 REs per port in the RB.

DMRS configuration type 2 may be classified as follows according to thenumber of OFDM symbols to which the front-loaded DMRS is allocated.

DMRS configuration type 2 and number of OFDM symbols to which thefront-loaded DMRS is allocated=1

Up to 6 ports (e.g., P0 to P5) may be multiplexed based on length-2F-CDM and FDM schemes. RS density may be set to 4 REs per port in theRB.

DMRS configuration type 2 and number of OFDM symbols to which thefront-loaded DMRS is allocated=2

Up to 12 ports (e.g., P0 to P11) may be multiplexed based on length-2F-CDM, length-2 T-CDM, and FDM schemes. If presence of the PT-RS isconfigured by higher layer signaling, T-CDM may be fixed to [1 1]. RSdensity may be set to 8 REs per port in the RB.

FIGS. 13A and 13B are diagrams schematically illustrating an example ofa front loaded DMRS of a first DMRS configuration type applicable to thepresent disclosure.

More specifically, FIG. 13A illustrates a front-loaded DMRS with onesymbol and FIG. 13B illustrates a front-loaded DMRS with two symbols.

In FIGS. 13A and 13B, A represents a DMRS offset value on the frequencyaxis. In this case, DMRS ports having the same DMRS offset A may besubjected to code division multiplexing in the frequency domain (CDM-F)or code division multiplexing in the time domain (CDM-T). In addition,DMRS ports having different DMRS offsets A may be subjected to CDM-F.

According to the present disclosure, CDM-F may be applied based on w_(f)^((k′)) of the following table and CDM-T may be applied based on w_(t)^((l′)) following table. In this case, k′ and l′ are parameter valuesfor determining subcarrier indexes to which corresponding DMRSs aremapped and may have values of 0 or 1. In addition, DMRSs correspondingto respective DMRS ports may be classified into CDM groups as shown inthe following tables as according to the DMRS configuration type.

Table 4 shows parameters for the first DMRS configuration type for aPDSCH and Table 5 shows parameters for the second DMRS configurationtype for the PDSCH.

TABLE 4 CDM group w_(f)(k′) w_(t)(l′) p λ Δ k′ = 0 k′ = 1 l′ = 0 l′ = 11000 0 0 +1 +1 +1 +1 1001 0 0 +1 −1 +1 +1 1002 1 1 +1 +1 +1 +1 1003 1 1+1 −1 +1 +1 1004 0 0 +1 +1 +1 −1 1005 0 0 +1 −1 +1 −1 1006 1 1 +1 +1 +1−1 1007 1 1 +1 −1 +1 −1

TABLE 5 CDM group w_(f)(k′) w_(t)(l′) p λ Δ k′ = 0 k′ = 1 l′ = 0 l′ = 11000 0 0 +1 +1 +1 +1 1001 0 0 +1 −1 +1 +1 1002 1 2 +1 +1 +1 +1 1003 1 2+1 −1 +1 +1 1004 2 4 +1 +1 +1 +1 1005 2 4 +1 −1 +1 +1 1006 0 0 +1 +1 +1−1 1007 0 0 +1 −1 +1 −1 1008 1 2 +1 +1 +1 −1 1009 1 2 +1 −1 +1 −1 1010 24 +1 +1 +1 −1 1011 2 4 +1 −1 +1 −1

A UE may acquire DMRS port configuration information configured by a BSthrough the DCI. For example, the UE may acquire the DMRS portconfiguration information through an antenna port field of DCI format1_1, based on a DMRS configuration type (e.g., the first DMRSconfiguration type (dmrs-Type=1) or the second DMRS configuration type(dmrs-Type=2)) configured for the UE and the maximum number of OFDMsymbols (e.g., maxLength=1 or maxLength=2) for a DL front-loaded DMRS.More specifically, Table 6 shows the DMRS port configuration informationaccording to the value of the antenna port field when dmrs-Type=1 andmaxLength=1 are configured for the UE. Table 7 shows the DMRS portconfiguration information according to the value of the antenna portfield when dmrs-Type=1 and maxLength=2 are configured for the UE. Table8 shows the DMRS port configuration information according to the valueof the antenna port field when dmrs-Type=2 and maxLength=1 areconfigured for the UE. FIG. 9 shows the DMRS port configurationinformation according to the value of the antenna port field whendmrs-Type=2 and maxLength=2 are configured for the UE.

TABLE 6 One Codeword: Codeword 0 enabled, Codeword 1 disabled Number ofDMRS CDM group(s) DMRS Value without data port(s) 0 1 0 1 1 1 2 1 0.1 32 0 4 2 1 5 2 2 6 2 3 7 2 0.1 8 2 2.3 9 2 0-2 10 2 0-3 11 2 0.2 12-15Reserved Reserved

TABLE 7 One Codeword: Two Codewords: Codeword 0 enabled, Codeword 0enabled, Codeword 1 disabled Codeword 1 enabled Number of Number of DMRSCDM Number of DMRS CDM Number of group(s) DMRS front-load group(s)front-load Value without data port(s) symbols Value without data DMRSport(s) symbols  0 1 0 1 0 2 0-4 2  1 1 1 1 1 2 0, 1, 2, 3, 4, 6 2  2 10, 1 1 2 2 0, 1, 2, 3, 4, 5, 6 2  3 2 0 1 3 2 0, 1, 2, 3, 4, 5, 6, 7 2 4 2 1 1 4-31 reserved reserved reserved  5 2 2 1  6 2 3 1  7 2 0, 1 1 8 2 2, 3 1  9 2 0-2 1 10 2 0-3 1 11 2 0, 2 1 12 2 0 2 13 2 1 2 14 2 2 215 2 3 2 16 2 4 2 17 2 5 2 18 2 6 2 19 2 7 2 20 2 0, 1 2 21 2 2, 3 2 222 4, 5 2 23 2 6, 7 2 24 2 0, 4 2 25 2 2, 6 2 26 2 0, 1, 4 2 27 2 2, 3, 62 28 2 0, 1, 4, 5 2 29 2 2, 3, 6, 7 2 30 2 0, 2, 4, 6 2 31 ReservedReserved Reserved

TABLE 8 One codeword: Two codewords: Codeword 0 enabled, Codeword 0enabled, Codeword 1 disabled Codeword 1 enabled Number of Number of DMRSCDM DMRS CDM group(s) DMRS group(s) Value without data port(s) Valuewithout data DMRS port(s) 0 1 0 8 3 0-4 1 1 1 1 3 0-5 2 1 0.1 2-31reserved reserved 3 9 0 4 2 1 5 2 2 6 2 3 7 2 0.1 8 2 2.3 9 9 0-2 10 90-3 11 3 0 12 3 1 13 3 2 14 3 3 15 3 4 16 3 5 17 3 0.1 18 3 2.3 19 3 4.520 3 0-2 21 3 3-5 22 3 0-3 23 2 0.2 24-31 Reserved Reserved

TABLE 9 One codeword: Two Codewords: Codeword 0 enabled, Codeword 0enabled, Codeword 1 disabled Codeword 1 enabled Number of Number of DMRSCDM Number of DMRS CDM Number of group(s) DMRS front-load group(s)front-load Value without data port(s) symbols Value without data DMRSport(s) symbols 0 1 0 1 0 3 0-4 1 1 1 1 1 1 3 0-5 1 2 1 0, 1 1 2 2 0, 1,2, 3, 6 2 3 2 0 1 3 2 0, 1, 2, 3, 6, 8 2 4 2 1 1 4 2 0, 1, 2, 3, 6, 7, 82 5 2 2 1 5 2 0, 1, 2, 3, 6, 7, 8, 9 2 6 2 3 1 6-63 Reserved ReservedReserved 7 2 0, 1 1 8 2 2, 3 1 9 2 0-2 1 10 2 0-3 1 11 3 0 1 12 3 1 1 133 2 1 14 3 3 1 15 3 4 1 16 3 5 1 17 3 0, 1 1 18 3 2, 3 1 19 3 4, 5 1 203 0-2 1 21 3 3-5 1 22 3 0-3 1 23 2 0, 2 1 24 3 0 2 25 3 1 2 26 3 2 2 273 3 2 28 3 4 2 29 3 5 2 30 3 6 2 31 3 7 2 32 3 8 2 33 3 9 2 34 3 10 2 353 11 2 36 3 0, 1 2 37 3 2, 3 2 38 3 4, 5 2 39 3 6, 7 2 40 3 8, 9 2 41 310, 11 2 42 3 0, 1, 6 2 43 3 2, 3, 8 2 44 3 4, 5, 10 2 45 3 0, 1, 6, 7 246 3 2, 3, 8, 9 2 47 3 4, 5, 10, 11 2 48 1 0 2 49 1 1 2 50 1 6 2 51 1 72 52 1 0, 1 2 53 1 6, 7 2 54 2 0, 1 2 55 2 2, 3 2 56 2 6, 7 2 57 2 8, 92 58-63 Reserved Reserved Reserved

In this case, the UE may perform DMRS reception according to a conditionas follows.

In DMRS configuration type 1,

-   -   one codeword may be scheduled for the UE and DCI indicating one        of {2, 9, 10, 11, 30} may be allocated to the UE as an index        value (e.g., an index value of Table 6 or Table 7) related to        antenna port mapping.    -   If two codewords are scheduled for the UE,

the UE may receive a DMRS under the assumption that all other orthogonalantenna ports are not associated with PDSCH transmission to other UEs.

In DMRS setting type 2,

-   -   one codeword is scheduled for the UE and DCI indicating one of        {2, 10, 23} may be allocated to the UE as an index value (e.g.,        an index value of Table 8 or Table 9) related to antenna port        mapping.    -   If two codewords are scheduled for the UE,

the UE may receive a DMRS under the assumption that all other orthogonalantenna ports are not associated with PDSCH transmission to other UEs.

1.5. DCI Format

In the NR system to which the present disclosure is applicable, thefollowing DCI formats may be supported. First, the NR system may supportDCI format 0_0 and DCI format 0_1 as a DCI format for PUSCH schedulingand support DCI format 1_0 and DCI format 1_1 as a DCI format for PDSCHscheduling. In addition, as DCI formats usable for other purposes, theNR system may additionally support DCI format 2_0, DCI format 2_1, DCIformat 2_ 2, and DCI format 2_3.

Herein, DCI format 0_0 is used to schedule a transmission block(TB)-based (or TB-level) PUSCH. DCI format 0_1 may be used to schedule aTB-based (or TB-level) PUSCH or code block group (CBG)-based (orCBG-level) PUSCH (in the case in which CBG-based signal transmission andreception is configured).

In addition, DCI format 1_0 may be used to schedule TB-based (orTB-level) PDSCH. DCI format 1_1 may be used to schedule TB-based (orTB-level) PDSCH or CBG-based (or CBG-level) PDSCH (in the case in whichCBG-based signal transmission and reception is configured).

In addition, DCI format 2_0 may be used to notify UEs of a slot format.DCI format 2_1 may be used to notify UEs of PRB(s) and OFDM symbol(s) inwhich a specific UE assumes that no transmission is intended therefor.DCI format 2_2 may be used to transmit transmission power control (TPC)commands for a PUCCH and a PUSCH. DCI format 2_3 may be used to transmita group of TPC commands for SRS transmission by one or more UEs.

More specifically, DCI format 1_1 may include modulation and codingscheme (MCS)/new data indicator (NDI)/redundancy version (RV) fields forTB 1 and further include MCS/NDI/RV fields for TB 2 only when a higherlayer parameter maxNrofCodeWordsScheduledByDCI in a higher layerparameter PDSCH-Config is set to n2 (i.e., 2).

In particular, when the higher layer parametermaxNrofCodeWordsScheduledByDCI is set to n2 (i.e., 2), whether a TB issubstantially enabled/disabled may be determined by a combination of theMCS field and the RV field. More specifically, when the MCS field for aspecific TB has a value of 26 and the RV field for the specific TB has avalue of 1, the specific TB may be disabled.

Detailed features of the DCI formats may be supported by 3GPP TS 38.212.That is, obvious steps or parts which are not explained by DCIformat-related features may be explained with reference to the abovedocument. In addition, all terms disclosed in the present document maybe explained by the above standard document.

1.6. Control Resource Set (CORESET)

One CORESET includes N^(CORESET) _(RB) RBs in the frequency domain andN^(CORESET) _(symb) symbols (having a value of 1, 2, or 3) in the timedomain.

One control channel element (CCE) includes 6 resource element groups(REGs) and one REG is equal to one RB in one OFDM symbol. REGs in theCORESET are numbered in a time-first manner. Specifically, the REGs arenumbered starting with ‘0’ for the first OFDM symbol and thelowest-numbered RB in the CORESET.

A plurality of CORESETs may be configured for one UE. Each CORESET isrelated only to one CCE-to-REG mapping.

CCE-to-REG mapping for one CORESET may be interleaved ornon-interleaved.

Configuration information for the CORESET may be configured by a higherlayer parameter ControlResourceSet IE.

In addition, configuration information for CORESET 0 (e.g., commonCORESET) may be configured by a higher layer parameterControlResourceSetZero IE.

1.7. Antenna Port Quasi Co-Location

One UE may be configured with a list of up to M transmissionconfiguration indicator (TCI) state configurations. The M TCI-stateconfigurations may be configured by a higher layer parameterPDSCH-Config to decode a PDSCH (by the UE) according to a detected PDCCHwith DCI intended for the UE and the given serving cell. Herein, M maybe determined depending on the capability of the UE.

Each TCI state contains parameters for configuring a quasi co-location(QCL) relationship between one or two DL reference signals and the DMRSports of the PDSCH. The QCL relationship is configured by the higherlayer parameter qcl-Type 1 for a first DL RS and a higher layerparameter qcl-Type2 for a second DL RS (if configured). For the case oftwo DL RSs, the QCL types should not be the same, regardless of whetherthe RSs are the same DL RS or different DL RSs. The QCL typecorresponding to each DL RS is given by a higher layer parameterqcl-Type within a higher layer parameter QCL-Info and may have one ofthe following values.

-   -   ‘QCL-TypeA’: {Doppler shift, Doppler spread, average delay,        delay spread}    -   ‘QCL-TypeB’: {Doppler shift, Doppler spread}    -   ‘QCL-TypeC’: {Doppler shift, average delay}    -   ‘QCL-TypeD’: {Spatial Rx parameter}

The UE receives an activation command used to map up to 8 TCI states tocodepoints of a TCI field in the DCI. When a HARQ-ACK signalcorresponding to the PDSCH carrying the activation command istransmitted in slot #n, mapping between the TCI states and codepoints ofthe TCI field in the DCI may be applied starting from slot#(n+3*N^(subframe,μ) _(slot+1)). In this case, N^(subframe,μ) _(slot) isdetermined based on Table 1 or Table 2 described above. After the UEreceives initial higher layer configuration of TCI states and before theUE receives the activation command, the UE assumes that DM-RS port(s) ofa PDSCH of a serving cell are quasi co-located with an SS/PBCH blockdetermined in the initial access procedure with respect to ‘QCL-TypeA’.Additionally, the UE may assume that the DM-RS port(s) of the PDSCH ofthe serving cell are quasi co-located with the SS/PBCH block determinedin the initial access procedure also with respect to ‘QCL-TypeD’ at theabove timing.

If a higher layer parameter tci-PresentInDCI is set as ‘enabled’ for aCORESET scheduling the PDSCH, the UE assumes that the TCI field ispresent in a PDCCH of DCI format 1_1 transmitted on the CORESET. If thehigher layer parameter tci-PresentInDCI is not configured for theCORESET scheduling the PDSCH or the PDSCH is scheduled by DCI format 1_0and if a time offset between the reception of the DL DCI and thereception of the corresponding PDSCH is equal to or greater than athreshold Threshold-Sched-Offset (where the threshold is based on UEcapability), for determining PDSCH antenna port QCL, the UE assumes thata TCI state or QCL assumption for the PDSCH is identical to a TCI stateor QCL assumption applied to a CORESET used for PDCCH transmission.

If the higher layer parameter tci-PresentInDCI is set as ‘enabled’, theTCI field in the DCI scheduling a component carrier (CC) points toactivated TCI states in the scheduled CC or a DL BW, and the PDSCH isscheduled by DCI format 1_1, the UE uses a TCI-state according to theTCI field in the DCI in a detected PDCCH to determine PDSCH antenna portQCL. The UE may assume that DMRS ports of the PDSCH of a serving cellare quasi co-located with RS(s) in the TCI state with respect to QCLtype parameter(s) given by an indicated TCI state if the time offsetbetween the reception of the DL DCI and the reception of thecorresponding PDSCH is equal to or greater than the thresholdThreshold-Sched-Offset (where the threshold is determined based onreported UE capability). When the UE is configured with a single slotPDSCH, the indicated TCI state should be based on the activated TCIstates in a slot with the scheduled PDSCH. When the UE is configuredwith CORESET associated with a search space set for cross-carrierscheduling, the UE expects that the higher layer parametertci-PresentInDci is set as ‘enabled’ for the CORESET. If one or more ofthe TCI states configured for the serving cell scheduled by the searchspace set contains ‘QCL-TypeD’, the UE expects the time offset betweenthe reception of the detected PDCCH in the search space set and thereception of the corresponding PDSCH is greater than or equal to thethreshold timeDurationForQCL.

For both the cases when higher layer parameter tci-PresentInDCI is setto ‘enabled’ and the higher layer parameter tci-PresentInDCI is notconfigured in RRC connected mode, if the offset between the reception ofthe DL DCI and the reception of the corresponding PDSCH is less than thethreshold Threshold-Sched-Offset, the UE makes the followingassumptions. (i) DM-RS ports of a PDSCH of a serving cell are quasico-located with the RS(s) in a TCI state with respect to QCLparameter(s). (ii) In this case, the QCL parameter(s) are used for PDCCHQCL indication of the CORESET associated with a monitored search spacewith the lowest CORESET-ID in the latest slot in which one or moreCORESETs within an active BWP of the serving cell are monitored by theUE.

In this case, if the ‘QCL-TypeD’ of a PDSCH DM-RS is different from‘QCL-TypeD’ of a PDCCH DM-RS with which overlapping occurs in at leastone symbol, the UE is expected to prioritize the reception of the ePDCCHassociated with the corresponding CORESET. This operation may also beapplied to an intra-band CA case (when the PDSCH and the CORESET are indifferent CCs). If none of configured TCI states contains ‘QCL-TypeD’,the UE obtains the other QCL assumptions from the indicated TCI statesfor a scheduled PDSCH irrespective of the time offset between thereception of the DL DCI and the reception of the corresponding PDSCH.

For a periodic CSI-RS resource in an NZP-CSI-RS-ResourceSet configuredwith a higher layer parameter trs-Info, the UE should assume that that aTCI state indicates one of the following QCL type(s):

-   -   ‘QCL-TypeC’ with an SS/PBCH block and, when (QCL-TypeD) is        applicable, ‘QCL-TypeD’ with the same SS/PBCH block, or    -   ‘QCL-TypeC’ with an SS/PBCH block and, when (QCL-TypeD) is        applicable, ‘QCL-TypeD’ with a periodic CSI-RS resource in a        higher layer parameter NZPCSI-RS-ResourceSet configured with        higher layer parameter repetition,

For a CSI-RS resource in the higher layer parameterNZP-CSI-RS-ResourceSet configured with the higher layer parametertrs-Info and without the higher layer parameter repetition, the UEshould assume that a TCI state indicates one of the following QCLtype(s):

-   -   ‘QCL-TypeA’ with a CSI-RS resource in the higher layer parameter        NZP-CSI-RS-ResourceSet configured with higher layer parameter        trs-Info and, when (QCL-TypeD) is applicable, ‘QCL-TypeD’ with        the same CSI-RS resource, or    -   ‘QCL-TypeA’ with a CSI-RS resource in the higher layer parameter        NZP-CSI-RS-ResourceSet configured with higher layer parameter        trs-Info and, when (QCL-TypeD) is applicable, ‘QCL-TypeD’ with        an SS/PBCH, or    -   ‘QCL-TypeA’ with a CSI-RS resource in the higher layer parameter        NZP-CSI-RS-ResourceSet configured with the higher layer        parameter trs-Info and, when (QCL-TyepD is) applicable,        ‘QCL-TypeD’ with a periodic CSI-RS resource in the higher layer        parameter NZP-CSI-RS-ResourceSet configured with the higher        layer parameter repetition, or    -   ‘QCL-TypeB’ with a CSI-RS resource in the higher layer parameter        NZP-CSI-RS-ResourceSet configured with the higher layer        parameter trs-Info when ‘QCL-TypeD’ is not applicable.

For a CSI-RS resource in the higher layer parameterNZP-CSI-RS-ResourceSet configured with the higher layer parameterrepetition, the UE should assume that a TCI state indicates one of thefollowing QCL type(s):

-   -   ‘QCL-TypeA’ with a CSI-RS resource in the higher layer parameter        NZP-CSI-RS-ResourceSet configured with the higher layer        parameter trs-Info and, when (13 QCL-TypeD) is applicable,        ‘QCL-TypeD’ with the same CSI-RS resource, or    -   ‘QCL-TypeA’ with a CSI-RS resource in the higher layer parameter        NZP-CSI-RS-ResourceSet configured with the higher layer        parameter trs-Info and, when (‘QCL-TypeD’ is) applicable,        ‘QCL-TypeD’ with a CSI-RS resource in the higher layer parameter        NZP-CSI-RS-ResourceSet configured with higher layer parameter        repetition, or    -   ‘QCL-TypeC’ with an SS/PBCH block and, when (QCL-TypeD) is        applicable, ‘QCL-TypeD’ with the same SS/PBCH block.

For the DM-RS of PDCCH, the UE should assume that a TCI state indicatesone of the following QCL type(s):

-   -   ‘QCL-TypeA’ with a CSI-RS resource in the higher layer parameter        NZP-CSI-RS-ResourceSet configured with the higher layer        parameter trs-Info and, when (QCL-TypeD) is applicable,        ‘QCL-TypeD’ with the same CSI-RS resource, or    -   ‘QCL-TypeA’ with a CSI-RS resource in the higher layer parameter        NZP-CSI-RS-ResourceSet configured with higher layer parameter        trs-Info and, when (QCL-TypeD) is applicable, ‘QCL-TypeD’ with a        CSI-RS resource in the higher layer parameter        NZP-CSI-RS-ResourceSet configured with the higher layer        parameter repetition, or    -   ‘QCL-TypeA’ with a CSI-RS resource in the higher layer parameter        NZP-CSI-RS-ResourceSet configured without higher layer parameter        trs-Info and without the higher layer parameter repetition and,        when (QCL-TypeD) is applicable, ‘QCL-TypeD’ with the same CSI-RS        resource.

For the DM-RS of the PDSCH, the UE should assume that a TCI stateindicates one of the following QCL type(s):

-   -   ‘QCL-TypeA’ with a CSI-RS resource in the higher layer parameter        NZP-CSI-RS-ResourceSet configured with the higher layer        parameter trs-Info and, when (QCL-TypeD) is applicable,        ‘QCL-TypeD’ with the same CSI-RS resource, or    -   ‘QCL-TypeA’ with a CSI-RS resource in the higher layer parameter        NZP-CSI-RS-ResourceSet configured with the higher layer        parameter trs-Info and, when (QCL-TypeD) is applicable,        ‘QCL-TypeD’ with a CSI-RS resource in the higher layer parameter        NZP-CSI-RS-ResourceSet configured with the higher layer        parameter repetition, or    -   QCL-TypeA’ with a CSI-RS resource in the higher layer parameter        NZP-CSI-RS-ResourceSet configured without the higher layer        parameter trs-Info and without the higher layer parameter        repetition and, when (QCL-TypeD) is applicable, ‘QCL-TypeD’ with        the same CSI-RS resource.

2. Proposed Embodiment

Hereinafter, a configuration proposed in the present disclosure will bedescribed in detail based on the above technical idea and scope.

In the following description, T/F resources may refer to time and/orfrequency resources.

In the following description, a case in which T/F resources ofrespective PDSCHs (e.g., PDSCH #0 and PDSCH #1) transmitted in differenttransmission and reception points (TRPs) (or beams or panels) overlap isassumed. In this case, the case in which the T/F resources overlap mayinclude all 5 cases illustrated in FIG. 14. In addition, according toembodiments in the following description, the “TRP” may be extensivelyinterpreted as a “beam” or a “signal (spatial) resource”.

FIG. 14 is a diagram illustrating cases in which two PDSCHs overlap ontime and/or frequency resources, which are applicable to the presentdisclosure.

As illustrated in FIG. 14, two PDSCHs may partially overlap (e.g., Case#1 to Case #3) or may overlap in one of the time domain or frequencydomain of two PDSCHs (e.g., Case #4 and Case #5). In Cases #1, #2, and#3 of FIG. 14, two PDSCHs (partially) overlap in both time andfrequency. In Case #4 of FIG. 14, two PDSCHs do not overlap only on thetime axis. In Case #5 of FIG. 14, two PDSCHs overlap in the time axisbut do not overlap in the frequency axis.

In the following description, when PDSCHs transmitted respectively indifferent TRPs (or beams) (partially) overlap on time-axis resources(e.g., Case #5) or (partially) overlap on time-axis and frequency-axesresources (e.g., case #1, #2, #3), transmission of the two PDSCHs isreferred to as non-coherent joint transmission (NC-JT).

In the following description, NC-JT based on single DCI (hereinafterreferred to as single-DCI based NC-JT, for convenience of description)means that PDSCHs transmitted respectively in different TRPs (or beams)are scheduled by one DCI. For example, single-DCI based NC-JT mayinclude a configuration in which DCI #1 simultaneously schedules PDSCHs#1 and #2 for different TRPs.

In the following description, NC-JT based on multiple DCIs (hereinafterreferred to as multi-DCI based NC-JT, for convenience of description)means that PDSCHs transmitted respectively in different TRPs (or beams)are scheduled by respective DCIs. For example, multi-DCI based NC-JT mayinclude a configuration in which DCIs #1 and #2 simultaneously schedulePDSCHs #1 and #2.

In the present disclosure, NC-JT may be classified into two casesdepending on whether layers transmitted by different TRPs areindependent or common.

For example, if layers are independent and if TRP #A transmits 3 layersand TRP #B transmits 4 layers, the UE may expect that a total of 7layers is transmitted. If layers are common and if TRP #A transmits 3layers and TRP #B transmits 3 layers, the UE may expect that a total of3 layers is transmitted.

To distinguish between the two cases, NC-JT of the former may bereferred to as NC-JT with independent layer (IL) and NC-JT of the lattermay be referred to as NC-JT with common layer (CL).

Although technical configurations proposed in the present disclosure arebasically based on NC-JT with IL, the configurations of the presentdisclosure are not limited thereto and may be extended to NC-JT with CL.

Hereinafter, a signaling method which is applicable when an NC-JTsituation is configured for a specific UE will be described in detail.

If a BS schedules different PDSCHs on (partially or fully) overlappingT/F resources using two DCIs for a specific UE, this may be similar tothe case in which the specific UE is multiplexed with another UE. Thisis because a PDSCH scheduled by one DCI acts as interference with aPDSCH scheduled by another DCI (or vice versa).

Accordingly, the UE may design reception filters or differently definereception beams so as to minimize interference between different PDSCHs(e.g., the UE may receive two PDSCHs through different reception beams).

However, the UE may miss one of the two DCIs in some cases. In thiscase, missing of a signal may mean that the UE fails to recognize thatthe signal itself has been transmitted or the UE fails to normallydetect/decode the signal although the UE recognizes that the signal hasbeen transmitted. Accordingly, the UE may not be aware of (i.e., may notrecognize) transmission of a PDSCH itself scheduled by the missed DCI.Then, the UE should recognize the presence of the PDSCH scheduled by themissed DCI through blind detection. That is, this may increase thecomplexity of the UE.

Therefore, even if the UE misses specific DCI, signaling through whichthe UE can recognize an NC-JT state may be needed. In particular, whenthe UE may receive the two PDSCHs using two different reception beams,the UE may implement the reception beams to minimize interferencebetween the two PDSCHs through corresponding signaling.

According to the recent 5G NR standard of 3GPP Rel-15, only onereference signal (RS) set is defined for one TCI state, and only one TCIstate is defined to be configured for one UE. Based on the abovedefinition, the present disclosure provides a signaling method to causea specific UE to recognize an NC-JT situation by configuring two or moreRS sets for the TCI state or configuring two or more TCI states for thespecific UE.

In this case, the UE is provided with two RS sets. However, the UE mayhave ambiguity as to which RS set provides QCL information (e.g.,spatial QCL) of a DMRS associated with a PDSCH scheduled bycorresponding DCI. Therefore, in the present disclosure, a signalingmethod of informing the UE of which RS set should be applied by anexplicit or implicit method will be described in detail.

In the present disclosure, the BS may indicate single-DCI or multi-DCIbased NC-JT to the UE by defining/configuring a plurality of RS sets forone TCI state. Next, the BS may provide additional information to the UEso that the UE may select an RS set related to QCL information of aPDSCH scheduled by DCI among a plurality of configured RS sets. Forexample, the BS may provide the additional information to the UE usingCW and/or DMRS port related field information of the DCI.

Alternatively, in the present disclosure, the BS may define one RS setfor one TCI state and indicate/configure a plurality of TCI statesto/for the UE through specific DCI. Through this, the BS may indicatesingle-DCI or multi-DCI based NC-JT to the UE. In this case, as a methodfor the UE to select an RS set related to QCL information of a PDSCHscheduled by DCI among a plurality of configured RS sets, the existingmethod of searching for one RS set from the plural RS sets describedabove may be applied.

Therefore, in all methods proposed below, if “one TCI state for whichtwo or more RS sets are defined is indicated to the UE” is changed to“two or more TCI states are indicated to the UE through one DCI”, then“one RS set is selected from among a plurality of RS sets” may beextended to “one TCI state is selected from among a plurality of TCIstates” in all methods.

In all of the following methods, NC-JT may mean NC-JT with IL. However,all configurations proposed in the present disclosure are not limitedonly to NC-JT with IL and may be extended to NC-JT with CL, coherentjoint transmission (C-JT) with IL, and C-JT with CL.

In all of the following methods, at least one of the following signalingmethods may be applied as a method of signaling the UE that NC-JT isapplied/configured. However, the following examples are only examplesapplicable to the present disclosure and a configuration proposed in allthe following methods may be equally applied even to other signalingmethods of signaling that NC-JT is applied/configured other than thefollowing examples.

(1) The BS may signal the UE that single-DCI or multi-DCI based NC-JT isapplied/configured by defining a plurality of RS sets for one TCI state.

(2) The BS may signal the UE that single-DCI or multi-DCI based NC-JT isapplied/configured by defining one RS set for one TCI set and indicatinga plurality of TCI states to the UE through single DCI.

(3) A radio network temporary identifier (RNTI) and a cell-RNTI (C-RNTI)for NC-JT may be differently defined. Then, the BS may signal the UEthat NC-JT is applied/configured by transmitting scrambled DCI to the UEusing the RNTI for NC-JT rather than the C-RNTI. Then, if the UEsuccessfully decodes received DCI using the RNTI for NC-JT, the UE mayrecognize that the BS has indicated NC-JT to the UE.

Hereinbelow, in all methods, DCI(s) paired with NC-JT may mean thatrespective PDSCHs scheduled by the DCI(s) (partially) overlap on T/Fresources.

2.1. Method 1

When two or more RS sets for one TCI state are defined by the BS, the UEmay recognize that an NC-JT mode/state is configured/defined withrespect thereto. In this case, each RS set may include QCL information(e.g., spatial QCL) for a DMRS of a PDSCH corresponding thereto.

For example, it is assumed that the BS transmits a signal to a specificUE through different TRPs based on the NC-JT mode/state. To this end,the BS may signal, using two DCIs, the specific UE that the NC-JTmode/state is configured.

In this case, when the specific UE has successfully decoded one DCI, thespecific UE may be aware of not only spatial QCL information of a DMRSassociated with a PDSCH scheduled by the successfully decoded DCI butalso spatial QCL information of a DMRS associated with a PDSCH scheduledby the other DCI, regardless of whether the other DCI has beensuccessfully decoded. This is because the specific UE may obtain spatialQCL information of DMRSs associated with respective PDSCHs through aplurality of RS sets in the successfully decoded DCI.

Accordingly, when the specific UE may receive the two PDSCHs using twodifferent reception beams, the specific UE may implement reception beamscapable of minimizing interference between the two PDSCHs even if the UEhas successfully decoded only one DCI.

2.2. Method 2

When the BS indicates one TCI state for which two or more RS sets aredefined to the UE, the UE may expect information indicating which RS setof the plural RS sets is related to a PDSCH (or a DMRS associated withthe PDSCH) scheduled by corresponding DCI. For example, in the abovecase, the UE may expect that information indicating which RS set of theplural RS sets is related to QCL information applied to the PDSCH (orthe DMRS associated with the PDSCH) scheduled by the corresponding DCIis received from the BS. In this case, the information may betransmitted and received based on higher layer signaling (e.g., RRC, amedia access control (MAC) control element (CE), and/or DCI).

As an example, when two RS sets are defined for one TCI state, it isassumed that the BS indicates the following TCI state to the UE.

TCI state #0={RS set #A, RS set #B}

In this case, when the BS transmits DCI indicating RS set #B to the UE,the UE may assume that QCL information derived from RS set #B is appliedto a DMRS associated with a PDSCH scheduled by the DCI.

2.3. Method 3

When the BS indicates one TCI state for which two or more RS sets aredefined to the UE, the UE may expect that (without explicit signaling)QCL information derived from an RS set defined at a specific position(e.g., the leftmost (or first) or rightmost (or last) position) amongthe plural RS sets is applied to a DMRS associated with a PDSCHscheduled by corresponding DCI.

For example, the BS may indicate/configure two TCI states to/for the UEthrough higher layer signaling (e.g., RRC) as follows.

TCI state #0={RS set #A, RS set #B}, TCI state #1={RS set #B, RS set #A}

Although combinations of RS sets defined for the two TCI states are thesame, orders of the RS sets are different. Accordingly, it is assumedthat the UE expects that the QCL information derived from an RS setdefined at the leftmost (or first) position among the plural RS sets isapplied to the DMRS associated with the PDSCH scheduled by the DCI. Inthis case, when first DCI indicates TCI state #0, the UE mayexpect/assume that QCL information of a DMRS associated with a PDSCHscheduled by the first DCI is derived from RS set #A. In addition, whensecond DCI indicates TCI state #1, the UE may expect/assume that QCLinformation of a DMRS associated with a PDSCH scheduled by the secondDCI is derived from RS set #B.

Alternatively, the above-described configuration may be extended asfollows. For example, the BS may define a field indicating an RS setrelated to the QCL information to the UE with respect to an RS set asfollows. For example, the BS may indicate/configure the following TCIstate to/for the UE.

TCI state #0={RS set #A, 1, RS set #B, 0}, TCI state #1={RS set #A, 0,RS set #B, 1}

That is, the BS may define a 1-bit bitmap for each RS set and indicatean RS set associated with QCL information of a DMRS associated with aPDSCH scheduled by corresponding DCI using the bitmap (e.g., an RS setindicated by 1). As an example, when the BS indicates/configures TCIstate #0 to/for the UE, the UE may assume that QCL information derivedby RS set #A is applied to the DMRS associated with the PDSCH scheduledby the DCI.

According to this method, the BS may provide related information to theUE without explicit signaling (e.g., an additional DCI field).

2.4. Method 4

When the BS indicates/configures one TCI state for which two or more RSsets are defined to/for the UE, the BS may provide information about anRS set associated with a DMRS related to a PDSCH scheduled by DCI basedon an enabled CW among two CWs configured by the DCI.

In the NR system to which the present disclosure is applicable, the BSand the UE may transmit and receive signals using up to two CWs. To thisend, the DCI transmitted by the BS to the UE may include an NDI/MCS/RVfield for each CW.

Meanwhile, when two different TRPs transmit respective PDSCHs to one UEthrough (partially) overlapping T/F resources, there is a highpossibility that reception powers for the different TRPs are differentin terms of the UE. In consideration of this possibility, when two CWsare configured/defined, it may be desirable that the CWs beconfigured/defined for the respective TRPs. That is, the TRPs may bemapped to CWs 1:1.

More specifically, when the BS sets a higher layer parameter valuemaxNrofCodeWordsScheduledByDCI to 2 (or n2) for the UE, the UE mayassume that a maximum of two CWs is present. In this case, when the MCSand RV field values for a specific TB (or corresponding CW) in DCIreceived from the BS are set to 26 and 1, respectively, the UE maydisable the specific TB (or corresponding CW). If initial transmissionincludes two CWs and retransmission includes one CW (i.e., decreasedfrom two CWs to one CW), the BS may signal the UE which TB (orcorresponding CW) has been retransmitted through the above signalingmethod.

Similarly, when respective RS sets are mapped to the CWs 1:1, the samescheme may be applied.

More specifically, the UE may assume that CW #1 and CW #2 are mapped toRS set #A and RS set #B, respectively.

In this case, if CWs #1 and #2 of the DCI are disabled and enabled,respectively, the UE may derive QCL information of the DMRS associatedwith the PDSCH scheduled by the DCI from RS set #B. In other words, theUE may obtain the QCL information of the DMRS associated with the PDSCHscheduled by the DCI based on RS set #B.

In contrast, when CWs #1 and #2 of the DCI are enabled and disabled,respectively, the UE may derive QCL information of the DMRS associatedwith the PDSCH scheduled by the DCI from RS set #A. In other words, theUE may obtain the QCL information of the DMRS associated with the PDSCHscheduled by the DCI based on RS set #A.

In the above example, when two RS sets are configured/defined for oneTCI state while only one CW is enabled, the UE may recognize that anNC-JT state/mode is applied through multiple DCIs through correspondingsignaling.

According to such a method, an additional DCI field does not need to benewly defined. In other words, the method may be equally applied to theexisting NR system.

When the NC-JT state/mode is used, even if one DCI based on the abovemethod schedules only one CW, fields for two CWs should always beconfigured/defined in the DCI. Then, bits (e.g., 8 bits) of apredetermined size for an unused CW may be wasted.

In consideration of this situation, in a modification applicable to thepresent disclosure, the BS may configure only one CW and additionallyconfigure/define a 1-bit DCI field additionally indicating an RS setrelated to the one CW, instead of bits of a predetermined size for theunused CW. From this point of view, in a non-NC-JT state/mode, theabove-described signaling method may be limitedly applied only when thePDSCH scheduled by one DCI supports two CWs.

Additionally, when the higher layer parametermaxNrofCodeWordsScheduledByDCI is set to 1, the BS may additionallyconfigure/define a DCI field for selecting/indicating one of a pluralityof RS sets defined for a TCI state as in Method 2 described above. Onthe other hand, when the higher layer parametermaxNrofCodeWordsScheduledByDCI is set to 2, the BS may select/indicateone of the plural RS sets defined for the TCI state, using signalingindicating whether a CW is enabled/disabled, instead of the additionalDCI field, as in Method 4 described above.

2.5. Method 5

When the BS configures one TCI state for which two RS sets are definedfor the UE and all of two CWs configured by DCI are enabled, the UE mayexpect that a single-DCI based NC-JT mode/state is configured. On thecontrary, when the BS configures one TCI state for which two RS sets aredefined for the UE and only one of two CWs configured by the DCI isenabled, the UE may expect that a multi-DCI based NC-JT mode/state isconfigured.

In the above-described single-DCI based NC-JT mode/state, the BS mayschedule respective PDSCHs transmitted in plural TRPs through one DCI.Therefore, unlike the multi-DCI based NC-JT mode/state, the case inwhich the UE misses one of a plurality of DCIs scheduling the PDSCH on(partially) overlapping T/F resources does not occur in the single-DCIbased NC-JT mode/state.

More specifically, the UE according to the present disclosure mayexpect/assume that CWs #1 and #2 (or CWs #0 and #1) are mapped to RSsets #A and/#B, respectively. Alternatively, the UE may expect/assumethat CWs #1 and #2 (or CWs #0 and #1) are mapped to RS sets #B and #A,respectively.

When the BS indicates/configures one TCI state for which a plurality ofRS sets is defined to/for the UE and the number of CWs enabled by DCItransmitted by the BS to the UE is 2, the UE may derive QCL informationof DMRSs of respective PDSCHs including CWs #1 and #2 (or CWs #0 and #1)from RS sets #A and #B (single-DCI based NC-JT).

Alternatively, when the BS indicates/configures one TCI state for whicha plurality of RS sets is defined to/for the UE and only one CW isenabled (e.g., when CWs #1 and #2 (or CWs #0 and #1) are enabled anddisabled, respectively) by the DCI transmitted by the BS to the UE, theUE may derive QCL information of a DMRS of a PDSCH scheduled by the DCIfrom RS set #A (multi-DCI based NC-JT).

Alternatively, when the BS indicates/configures one TCI state for whicha plurality of RS sets is defined to/for the UE and only one CW isenabled by the DCI transmitted by the BS to the UE (e.g., when CWs #1and #2 (or CWs #0 and #1) are disabled and enabled, respectively), theUE may derive QCL information of a DMRS of a PDSCH scheduled by the DCIfrom RS set #B (multi-DCI based NC-JT).

2.6. Method 6

Hereinbelow, it is assumed that the BS indicates/configures one TCIstate for which a plurality of RS sets is defined to/for the UE and onlyone of two configured CWs is enabled by DCI transmitted by the BS to theUE. In this case, if the UE fails to receive another DCI before the UEreceives a PDSCH scheduled by the DCI or within a time window (or timer)after the DCI is received, the UE may report occurrence of NACK for thePDSCH scheduled by the DCI to the BS.

In Methods 1 to 5 described above, the following assumption is made: ifthe BS indicates/configures one TCI state for which a plurality of RSsets is defined to/for the UE and only one of two configured CWs isenabled by DCI transmitted by the BS to the UE, the UE may assume that afist PDSCH scheduled by the DCI and a second PDSCH scheduled by anotherDCI are configured to (partially) overlap on T/F resources. In thiscase, if the UE fails to receive the other DCI, this may mean that theUE has failed to perform DCI decoding although the BS has transmittedthe other DCI to the UE. Therefore, in this case, the UE may report NACKfor a PDSCH scheduled by the DCI that the UE has fails to decode the BS.

Meanwhile, when the UE misses one of the two DCIs, the UE may also missa PUCCH resource scheduled by the missed DCI. Then, the BS may haveambiguity about (1) whether the UE has missed DCI (by doing so, whetherthe UE has not performed ACK/NACK report) or (2) whether the BS hasfailed to decode ACK/NACK report although the UE has performed theACK/NACK report.

However, according to a method proposed in the present disclosure, ifthe UE succeeds in decoding only one of the two DCIs, the UE maysimultaneously report ACK/NACK signals for the two DCIs. Accordingly, inthe above case, the BS may exclude at least the case in which the BS hasfailed to decode a PUCCH for ACK/NACK from the cases in which ACK/NACKreport has not been received, on the grounds that the UE may performACK/NACK report even for missed DCI.

In the present disclosure, when the BS configures/indicates one TCIstate for which two or more RS sets are defined to/for the UE, the UEmay assume/expect that PDSCHs scheduled by different DCIs are present onthe same T/F resource. Accordingly, the UE may expect that the other DCIis transmitted before a time point at which the UE receives a PDSCHscheduled by received DCI.

Meanwhile, upon considering a time delay for DCI decoding, apredetermined time or more may be secured between a time point at whichthe other DCI is transmitted and a time point at which the PDSCH isreceived. Accordingly, when the other DCI is not received before aspecific time based on a PDSCH reception time, the UE may report NACKfor the PDSCH scheduled by the other DCI under the assumption thatdecoding for the other DCI has failed. Meanwhile, information about thepredetermined time may be configured for the UE through higher layer(e.g., RRC) signaling.

2.7. Method 7

It is assumed that the BS configures/indicates one TCI state for whichtwo or more RS sets are defined for/to the UE and only one of two CWs isenabled by DCI. In this case, the UE may expect that ACK/NACK signalsfor respective PDSCHs scheduled by DCI and another DCI paired with theDCI are multiplexed and transmitted on the same PUCCH resource.

More specifically, the UE may multiplex and transmit ACK/NACK for aPDSCH scheduled by the missed DCI according to Method 6 through a PUCCHresource indicated by DCI that has successfully been decoded.

To this end, the two DCIs should be configured to have the same PUCCHresource and the same transmission timing. Accordingly, when the UEsucceeds in decoding only one of the two DCIs, the UE may simultaneouslyreport ACK/NACK signals for the two DCIs to the BS.

In the above method, the UE may assume that up to one CW is scheduled byone DCI. Accordingly, when 2 bits are allocated for the PUCCH resource,the UE may simultaneously transmit ACK/NACK signals for two DCIs on thePUCCH resource.

As a modified example, the UE may expect that the most significant bit(MSB) and least significant bit (LSB) of ACK/NACK-related bitinformation are sequentially mapped one-to-one to CWs or RS sets,respectively.

More specifically, when the UE multiplexes and transmits ACK/NACKsignals for two DCIs, a rule for interpreting the multiplexed ACK/NACKinformation (e.g., 2-bit information) transmitted by the UE between theUE and the BS may be defined. In this case, considering that CWs #1 and#2 (or CWs #0 and #1) are mapped 1:1 to the RS sets defined for the TCIstate, the MSB and the LSB of the ACK/NACK information (e.g., 2-bitinformation) may correspond to or may be mapped to ACK/NACK signals of afirst CW and a second CW, respectively.

As another modified example, only when the BS configures/defines 8 orless PUCCH resources in the first PUCCH resource set (e.g., PUCCHresource set #1) among a plurality of PUCCH resource sets configured forthe UE, the UE may expect that ACK/NACK signals for PDSCHs scheduled bytwo DCIs are multiplexed and transmitted on the same PUCCH resource asin Method 7 described above.

More specifically, in the NR system to which the present disclosure isapplicable, a PUCCH resource for ACK/NACK reporting related to a PDSCHmay be determined based on RRC or DCI (e.g., ACK/NACK resource indicator(ARI) of DCI and/or an implicit control channel element (CCE) mapping ofthe DCI). In this case, when 8 or less PUCCH resources in the PUCCHresource set #1 are configured/defined, the BS and the UE may determinea PUCCH based only on the ARI of the DCI. In other words, irrespectiveof CCE mapping of the DCI, the BS may indicate the same PUCCH resource(for ACK/NACK) as PUCCH resources associated with PDSCHs scheduled bythe two DCIs.

Alternatively, even when more than 8 or more PUCCH resources in thefirst PUCCH resource set (e.g., PUCCH resource set #1) areconfigured/defined among a plurality of PUCCH resource sets configuredby the BS for the UE, the BS may configure the PUCCH resourcesassociated with the PDSCHs scheduled by the two DCIs to be equal bycontrolling CCE mapping of the two DCIs. In this case, the UE may stillexpect that ACK/NACK signals for respective PDSCHs scheduled by the twoDCIs are multiplexed and transmitted on the same PUCCH resource.

In the NR system to which the present disclosure is applicable, up to 32PUCCH resources may be configured in the first PUCCH resource set (e.g.,PUCCH resource set #1) and the PUCCH resource set may include 8 subsetseach including 4 PUCCH resources. In this case, the ARI field of DCIindicates one of the 8 subsets and one PUCCH resource in a subsetselected based on implicit CCE mapping of the DCI may beselected/determined. In consideration of such characteristics, thefollowing method may be considered such that the same PUCCH resource isallocated to the PDSCHs scheduled by the two DCIs.

-   -   If two or more RS sets are configured for one TCI state and a        multi-DCI based NC-JT mode/state is configured for the UE, the        UE may be configured/implemented to select a PUCCH resource        having a low index/ID from among PUCCH resources included in a        PUCCH subset (in PUCCH resource set #1) determined based on the        ARI in the DCI. In this case, even when the number of PUCCH        resources included in PUCCH resource set #1 is greater than 8,        the UE may expect that ACK/NACK signals for the PDSCHs scheduled        by two DCIs are multiplexed and transmitted on the same PUCCH        resource as in Method 7 regardless of implicit CCE mapping of        the DCIs.    -   On the other hand, as described above, the PUCCH resource        configured to multiplex ACK/NACK reports for the PDSCHs        scheduled by the two DCIs needs to be set to always have a size        greater than 2 bits. Accordingly, the UE may be        configured/implemented to select a PUCCH resource having a low        index/ID among PUCCH resources satisfying a size of 2 bits in a        PUCCH subset (in PUCCH resource set #1) determined based on the        ARI in the DCI. The above method is advantageous in that the UE        becomes free from restrictions on a condition that the PUCCH        resource having the lowest index/ID in a selected PUCCH resource        subset should always have a 2-bit size.    -   On the other hand, if the size of the PUCCH resource for the        PDSCHs scheduled by two DCI is greater than 2 bits, the PUCCH        resource is included in a PUCCH resource set other than the        first PUCCH resource set (e.g., PUCCH resource set #1)        (according to definition of the NR system). In the NR system,        the PUCCH resource set other than the first PUCCH resource set        is configured to include a maximum of 8 PUCCH resources. Thus,        when the size of the PUCCH resource for the PDSCHs scheduled by        two DCIs is greater than 2 bits, the BS may allocate/configure        the same PUCCH resource for the two DCIs (or related PUSCHs)        using the ARI field in the DCI.    -   In the above-described configuration, a PUCCH resource selected        for ACK/NACK multiplexing may be a PUCCH resource of an order        (e.g., third or fourth PUCCH resource) other than the first        PUCCH resource in a specific PUCCH resource set (or subset). To        this end, separate signaling (e.g., higher layer signaling        (e.g., RRC or a MAC-CE)) may be utilized.

2.8. Method 8

When the BS configures/indicates one TCI state for which two or more RSsets are defined for/to the UE, the UE may select an RS set thatprovides QCL information of a DMRS of a PDSCH scheduled by the DCI,based on a DMRS port number configured by the DCI or a combination ofDMRS port numbers.

2.8.1. Method 8-1

It is assumed that the BS configures/indicates one TCI state for whichtwo or more RS sets are defined for/to the UE and that a DMRS portindicated by DCI is included only in one specific DMRS port group or CDMgroup. In this case, the UE may select an RS set that provides the QCLinformation of the PDSCH DMRS scheduled by the DCI, based on informationabout the DMRS port group or the CDM group.

In the following description, “DMRS port group” may be changed to “CDMgroup”. In other words, all technical features applied to the “DMRS portgroup” in the following description may be equally applied to the “CDMgroup”.

The following table shows a DMRS port group set (or CDM group set)according to a DMRS type configuration. In a given configuration, oneDMRS port group may mean a combination of DMRS ports multiplexed byCDM-F and/or CDM-T. DMRS port groups (or CDM groups) #1/#2/#3/#4/#5/#6may have a sequentially associated relationship with the RS sets definedfor one TCI state in order.

In Table 10, each group may be categorized based on FDM.

TABLE 10 DMRS type DMRS type configuration = 1 configuration = 2 DMRSport group #1 {0, 1, 4, 5} {0, 1, 6, 7} (CDM group #1) DMRS port group#2 {2, 3, 6, 7} {2, 3, 8, 9} (CDM group #2) DMRS port group #3 {4, 5,10, 11} (CDM group #3)

In Table 11, each group may be categorized based on FDM or CDM-T.

TABLE 11 DMRS type DMRS type configuration = 1 configuration = 2 DMRSport group #1 {0, 1} {0, 1} (CDM group #1) DMRS port group #2 {2, 3} {2,3} (CDM group #2) DMRS port group #3 {4, 5} {4, 5} (CDM group #3) DMRSport group #4 {6, 7} {6, 7} (CDM group #4) DMRS port group #5 {8, 9}(CDM group #5) DMRS port group #6 {10, 11} (CDM group #6)

Hereinbelow, for convenience of description, related configurations willbe described based on the configurations of Table 10 unless explicitlystated otherwise for the configurations of Table 10. The configurationsmay be extended to the configurations of Table 11 without being limitedto the configurations of Table 10.

For example, it is assumed that the BS configures TCI state #0={RS set#A, RS set #B} and a higher layer parameter DMRS configuration-Type=1for the UE. If DMRS port numbers indicated by DCI (that schedules aPDSCH) belong to DMRS port group #1, the UE may assume that QCLinformation of the DMRS of the PDSCH scheduled by the DCI is derivedfrom RS set #A. Alternatively, when the DMRS port numbers indicated bythe DCI belong to DMRS port group #2, the UE may assume that the QCLinformation of the DMRS of the PDSCH scheduled by the DCI is derivedfrom RS set #B.

As another example, it is assumed that the BS configures a TCI state#0={RS set #A, RS set #B} (or TCI state #0={RS set #A, RS set #B, RS set#C}) and a higher layer parameter DMRS configuration-Type=2 for the UE.If the DMRS port numbers indicated by the DCI (that schedules the PDSCH)belong to DMRS port group #1, the UE may assume that the QCL informationof the DMRS of the PDSCH scheduled by the DCI is derived from RS set #A.Alternatively, if the DMRS port numbers indicated by the DCI belong toDMRS port group #2, the UE may assume that the QCL information of theDMRS of the PDSCH scheduled by the DCI is derived from RS set #B.Alternatively, if the DMRS port numbers indicated by the DCI belong tothe DMRS port group #3 (only when the TCI state #0={RS set #A, RS set#B, RS set #C}), the UE may assume that the QCL information of the DMRSof the PDSCH scheduled by the DCI is derived from the RS set #C.

-   -   It is assumed that the BS configures TCI state #0={RS set #A, RS        set #B} and the higher layer parameter DMRS configuration-Type=1        for the UE. Next, Table 12 shows DMRS port configuration        information when the DMRS configuration type is set to the first        DMRS configuration type and the maximum number of OFDM symbols        for a DL front-loaded DMRS is set to 2 as shown in Table 7.

Based on the above-described assumptions and the following table, whenvalue=2 (DMRS ports #0 and #1) is allocated for the UE, the UE mayassume that the QCL information of the DMRS of the PDSCH scheduled bythe DCI is derived from RS set #A. When value=8 (DMRS ports #2 and #3)is allocated to the UE, the UE may assume that the QCL information ofthe DMRS of the PDSCH scheduled by the DCI is derived from RS set #B.

TABLE 12 One Codeword: Two Codewords: Codeword 0 enabled, Codeword 0enabled, Codeword 1 disabled Codeword 1 enabled Number of Number of DMRSCDM Number of DMRS CDM Number of group(s) DMRS front-load group(s)front-load Value without data port(s) symbols Value without data DMRSport(s) symbols  0 1 0 1 0 2 0-4 2  1 1 1 1 1 2 0, 1, 2, 3, 4, 6 2  2 10, 1 1 2 2 0, 1, 2, 3, 4, 5, 6 2  3 2 0 1 3 2 0, 1, 2, 3, 4, 5, 6, 7 2 4 2 1 1 4-31 reserved reserved reserved  5 2 2 1  6 2 3 1  7 2 0, 1 1 8 2 2, 3 1  9 2 0-2 1 10 2 0-3 1 11 2 0, 2 1 12 2 0 2 13 2 1 2 14 2 2 215 2 3 2 16 2 4 2 17 2 5 2 18 2 6 2 19 2 7 2 20 2 0, 1 2 21 2 2, 3 2 222 4, 5 2 23 2 6, 7 2 24 2 0, 4 2 25 2 2, 6 2 26 2 0, 1, 4 2 27 2 2, 3, 62 28 2 0, 1, 4, 5 2 29 2 2, 3, 6, 7 2 30 2 0, 2, 4, 6 2 31 ReservedReserved Reserved

Methods 8-2, 8-3, and 8-4 described below are based on Methods 5, 6, and7, respectively, described above. However, Methods 8-2, 8-3, and 8-4 aredifferent from Methods 5, 6, and 7 in that the UE searches for an RS setthat provides the QCL information of the DMRS of the PDSCH from aplurality of RS sets defined for one TCI state, based on DMRS portrelated information, rather than CW related information configured bythe DCI.

2.8.2. Method 8-2

If the BS configures/indicates one TCI state for which two or more RSsets are defined for/to the UE and DMRS ports indicated by the DCIbelong to a plurality of different DMRS port groups, the UE may expect asingle-DCI based NC-JT mode/state. If the BS configures/indicates oneTCI state for which two or more RS sets are defined for/to the UE andDMRS ports indicated by the DCI are included only in one specific DMRSport group, the UE may expect a multi-DCI based NC-JT mode/state.

-   -   As an example, it is assumed that the BS configures TCI state        #0={RS set #A, RS set #B} and the higher layer parameter DMRS        configuration-Type=1 for the UE. In this case, when value=9        (DMRS ports #0, #1, and #2) of Table 12 is allocated to the UE,        the UE may assume/expect that QCL information of DMRS ports #0        and #1 is derived from RS set #A. In addition, the UE may        assume/expect that QCL information of DMRS port #2 is derived        from RS set #B. As a result, when a combination of DMRS ports        allocated to the UE is configured in the form of a mixture of        DMRS port group #1 and DMRS port group #2, the UE may interpret        corresponding signaling/configuration as the single-DCI based        NC-JT mode/state rather than the multi-DCI based NC-JT        mode/state.    -   As another example, it is assumed that the BS configures TCI        state #0={RS set #A, RS set #B} and the higher layer parameter        DMRS configuration-Type=1 for the UE. It is assumed that the        DMRS port group configured for the UE is based on Table 11. If        value=28 (DMRS ports #0, #1, #4, and #5) of Table 12 is        allocated to the UE, the UE may assume/expect that the QCL        information of DMRS ports #0 and #1 is derived from RS set #A.        and the QCL information of DMRS ports #4 and #5 is derived from        RS set #B. As a result, when a combination of the DMRS ports        allocated to the UE is configured in the form of a mixture of        DMRS ports belonging to different DMRS port groups, the UE may        interpret corresponding signaling/configuration as the        single-DCI based NC-JT mode/state rather than the multi-DCI        based NC-JT mode/state.    -   As another example, it is assumed that the BS configures the        higher layer parameter maxNrofCodeWordsScheduledByDCI=1 for the        UE and TCI state={RS set #A, RS set #B} and DMRS port={#0, #1,        #2, #3} are configured/indicated for/to the UE through the DCI.    -   In this case, since a combination of configured/indicated DMRS        ports is a mixture, the UE may interpret corresponding        signaling/configuration as the single-DCI based transmission        mode/state.    -   Accordingly, the transmission mode/state supports only a single        CW and the UE may expect that PDSCHs transmitted by two TRPs        corresponding to RS sets #A and #B are transmitted based on the        same MCS. The UE may assume that QCL information of DMRS ports        #0 and #1 is derived from RS set #A, and that QCL information of        DMRS ports #2 and #3 is derived from RS set #B.    -   Alternatively, when the BS configures the higher layer parameter        maxNrofCodeWordsScheduledByDCI=2 for the UE and disables a        specific CW of two CWs through the DCI (i.e., a specific field        value in the DCI is configured as a value indicating MCS=26 and        RV=1), MCS information configured/indicated for/to the UE is one        and the UE may perform the same signal transmission/reception        operation as in a single CW.    -   Alternatively, it is assumed that the BS configures the higher        layer parameter maxNrofCodeWordsScheduledByDCI=2 for the UE and        enables both CWs through the DCI.    -   In this case, the UE may expect that PDSCHs transmitted by two        TRPs corresponding to RS sets #A and #B are transmitted with        different MCSs. For example, the UE may expect that layers #0        and #1 corresponding to DMRS ports #0 and #1 are transmitted        based on MCS #0 and layers #2 and #3 corresponding to DMRS ports        #2 and #3 are transmitted based on MCS #1. Meanwhile, the UE may        assume/expect that QCL information of DMRS ports #0 and #1 is        derived from RS set #A and assume/expect that QCL information of        DMRS ports #2 and #3 is derived from RS set #B.

2.8.3. Method 8-3

It is assumed that the BS configures/indicates one TCI state for whichtwo or more RS sets are defined for/to the UE and an indicated DMRS portbelongs to only one DMRS port group. In this case, if the UE fails toreceive another DCI before the UE receives a PDSCH scheduled by DCI orwithin a time window (or timer) of a predetermined size after the DCI isreceived, the UE may report occurrence of NACK for the PDSCH scheduledby the DCI to the BS.

2.8.4. Method 8-4

It is assumed that the BS configures/indicates one TCI state for whichtwo or more RS sets are defined for/to the UE and an indicated DMRS portbelongs to only one DMRS port group. In this case, the UE may expectthat ACK/NACK signals for respective PDSCHs scheduled by the DCI andanother DCI paired with the DCI are multiplexed and transmitted on thesame PUCCH resource.

-   -   Additionally, when the BS configures the higher layer parameter        maxNrofCodeWordsScheduledByDCI=1 for the UE, the UE may expect a        1-bit PUCCH resource for ACK/NACK. However, even if the bit size        value is set to 1, when an NC-JT mode/state is        configured/indicated for/to the UE according to the        above-described various methods, the UE may expect/assume that a        2-bit PUCCH resource for ACK/NACK is configured (in spite of        configuration for the above bit size value).

2.9. Method 9

According to the method, the BS may separately define an RNTI for NC-JT.Accordingly, when the BS scrambles and transmits a cyclic redundancycheck (CRC) of DCI using the RNTI for NC-JT, if the CRC of received DCIis resolved (or if decoding is successful) by the RNTI for NC-JT, the UEmay interpret the DCI as DCI used for NC-JT.

2.10. Method 10

The BS may configure TCI states for NC-JT, which are distinguished fromTCI states for non-CoMP, through a higher layer parameter (e.g., RRCand/or MAC-CE) for the UE. In addition, when the UE successfully decodesDCI using the RNTI for NC-JT, the UE may receive one of the configuredTCI states for NC-JT through a TCI indication field in the DCI.

According to the above method, the BS may inform the UE of an NC-JTstate/mode based on the RNTI for NC-JT. Then, the UE may expect/assume aTCI state for which two or more RS sets are defined. Therefore,according to the above method, Methods 1 to 8 described above may beapplied (without further modification).

More specifically, according to the standard document of 3GPP TS 38.321in which the NR system to which the present disclosure is applicable isdefined (e.g., FIG. 6.1.3.14-1), a bitmap for each of (N-2) x8 TCIstates may be defined. If the bit (or field) of a corresponding TCIstate is defined as 0 or 1, this may mean that the TCI state isdeactivated or activated. Activated TCI states may be mapped 1:1 to DCIcodepoints in order of TCI state IDs. For example, when field values ofTCI state #0 to #7 are set to [0 1 1 0 0 0 1 1], a mapping relationshipbetween DCI codepoints and TCI states may be configured as shown in thefollowing table.

TABLE 13 Codepoint TCI state 00 #1 01 #2 10 #6 11 #7

Alternatively, the BS may configure TCI states for non-CoMP and TCIstates for NC-JT for the UE through a higher layer parameter (e.g.,RRC). In this case, 1-bit information (e.g., 0 or 1) existing next toeach RS set may indicate whether a corresponding TCI-state is activatedor deactivated.

(1) TCI states for Non-CoMP

-   -   TCI state #1={RS set #A}, 1    -   TCI state #2={RS set #B}, 1    -   TCI state #3={RS set #C}, 0    -   TCI state #4={RS set #D}, 0    -   TCI state #6={RS set #E}, 1    -   TCI state #7={RS set #F}, 1

(2) TCI states for CoMP

-   -   TCI state #8={RS set #A, RS set #B}, 0    -   TCI state #9={RS set #B, RS set #C}, 1    -   TCI state #10={RS set #C, RS set #A}, 1    -   TCI state #11={RS set #D, RS set #C}, 1    -   TCI state #12={RS set #D, RS set #E}, 0    -   TCI state #13={RS set #C, RS set #F}, 1

Additionally, according to the present disclosure, two tables may bedefined as shown below. In this case, if the UE successfully decodes DCIbased on a cell-RNTI (C-RNTI), the UE may expect/assume that the TCIfield of the DCI indicates one of TCI states for non-CoMP.

Next, if the UE succeeds in decoding the DCI based on the RNTI forNC-JT, the UE may expect/assume that the TCI field of the DCI indicatesone of TCI states for CoMP.

In the present disclosure, although it has been assumed that the size ofthe TCI field is 2 bits, the size of the TCI field may be extended to abit size other than 2 bits.

Tables 14 and 15 below show examples of tables applicable to TCI statesfor non-CoMP and TCI states for CoMP, respectively.

TABLE 14 Codepoint TCI state 00 #1 01 #2 10 #6 11 #7

TABLE 15 Codepoint TCI state 00  #9 01 #10 10 #11 11 #13

As another example, when the UE succeeds in decoding DCI based on theRNTI for NC-JT, the UE may expect/assume that another DCI scrambled bythe RNTI for NC-JT is transmitted. However, when the UE fails to receivethe other DCI before the UE receives a PDSCH scheduled by the DCI thatthe UE has successfully decoded or within a time window (or timer) of apredetermined size after the DCI that the UE has successfully decoded isreceived, the UE may report occurrence of NACK for a PDSCH scheduled bythe other DCI to the BS. In Method 6 described earlier, if the UE missesone of two DCIs paired in the NC-JT mode/state, an operation conditionof the UE related to ACK/NACK may be appreciated as a limitedconfiguration based on the RNTI for NC-JT in this method.

As another example, when the UE succeeds in decoding DCI based on theRNTI for NC-JT, the UE may expect/assume that another DCI scrambled bythe RNTI for NC-JT is transmitted. In this case, the UE mayexpect/assume that ACK/NACK signals for respective PDSCHs scheduled bythe two DCIs are multiplexed and transmitted on the same PUSCH resource.In Method 7 described above, the operation condition of the UE in whichthe ACK/NACK signals for respective PDSCHs scheduled by the two DCIs aremultiplexed and transmitted on the same PUSCH resource may be understoodas a limited configuration based on the RNTI for NC-JT in this method.

2.11. Method 11

When the BS configures/indicates an NC-JT mode/state for/to the UE, theUE may expect/assume a 2-bit PUCCH resource for ACK/NACK regardless of aconfiguration value of the higher layer parametermaxNrofCodeWordsScheduledByDCI.

In Methods 6 and 7 described above, even if the UE misses one of theDCIs paired in NC-JT, the UE may be configured to transmit NACK for thePDSCH scheduled by the missed DCI.

However, in the recent specification of the NR system to which thepresent disclosure is applicable, when the BS configures the higherlayer parameter maxNrofCodeWordsScheduledByDCI=1 for the UE, the UE mayexpect/assume a 1-bit PUCCH resource for ACK/NACK. In this case, Methods6 and 7 described above may not be satisfied. Accordingly, even if theBS configures the higher layer parametermaxNrofCodeWordsScheduledByDCI=1 for the UE according to the presentmethod, when the NC-JT mode/status is indicated to the UE, the UE mayexpect/assume a 2-bit PUCCH resource for ACK/NACK.

As a modified example, when a plurality of ACK/NACK PUCCH resources forrespective PDSCHs scheduled by the DCIs paired in the NC-JT mode/stateis configured/allocated in the same slot according to the above method,the UE may transmit ACK/NACK information by arbitrarily selecting one ofthe PUCCH resources.

More specifically, according to Method 7 described above, the BSallocates the same PUCCH resource of the same slot timing with respectto all PDSCHs scheduled by the DCIs paired in the NC-JT mode/state andthen the UE in the NC-JT mode/state may expect/assume a PUCCH resourcefor one ACK/NACK report. In this case, there may be an advantage thatPUCCH resources can be efficiently managed. However, for this purpose,dynamic coordination between TRPs or cells should be basically provided.If not, the BS may configure/indicate different PUCCH resources ofdifferent slot timings through respective DCIs for/to the UE.

Meanwhile, according to Method 11 described above, when the BSconfigures/indicates different PUCCH resources #0 and #1 of the sameslot timing through two DCIs paired in the NC-JT mode/state, the UEaccording to the modified example may transmit ACK/NACK through acorresponding PUCCH resource by randomly selecting one of the two PUCCHresources. This is because the two PUCCH resources are used to transmitthe same information so that there is no need to multiplex the two PUCCHresources.

Meanwhile, the UE may transmit ACK/NACK information by selecting a PUCCHresource indicated/allocated by DCI that schedules a PDSCH having a QCLrelationship with RS set #A located in the foremost position (orrearmost position) from TCI state={RS set #A, RS set #B}, rather thanrandomly selecting one of the two PUCCH resources.

FIGS. 15A and 15B are diagrams illustrating a signal transmission andreception operation between a UE and a BS (or a network) applicable tothe present disclosure.

As illustrated in FIG. 15A, the UE and the BS (or network) maysimultaneously transmit and receive a plurality of data (e.g., PDSCHs)through one TRP. To this end, the BS may transmit a plurality of DCIs tothe UE and transmit a plurality of PDSCHs related to the DCIs throughthe one TRP.

Alternatively, as illustrated in FIG. 15B, the UE and the BS maysimultaneously transmit and receive a plurality of data (e.g., PDSCHs)through a plurality of TRPs. To this end, the BS may transmit aplurality of DCIs to the UE and may transmit a plurality of PDSCHsrelated to the DCIs through the TRPs, respectively.

Hereinafter, a signal transmission and reception method between the UEand the BS applicable to all the above-described signaltransmission/reception operations will be described in detail.

FIG. 16 is a diagram illustrating operations of a UE and a BS applicableto the present disclosure. FIG. 17 is a flowchart illustrating anoperation of a UE according to the present disclosure. FIG. 18 is aflowchart illustrating an operation of a BS according to the presentdisclosure.

The UE receives DCI related to a plurality of TCI states from the BS (ornetwork) (S1610 and S1710). The BS transmits DCI related to theplurality of TCI states to the UE (S1610 and S1810).

Herein, if the plurality of TCI states are related to the DCI, this maymean that the plurality of TCI states related to one RS set areallocated to the UE by the DCI. In other words, when plurality of TCIstates (related to one RS set) are allocated to the UE by the DCI, thismay mean that the DCI is related to the plurality of TCI states.

In this case, the UE may assume that a second PDSCH scheduled for the UEis present so as to overlap with a first PDSCH scheduled by the DCI on atime resource, based on the plurality of TCI states related to onereference resource (RS) set, the plurality of TCI states being allocatedto the UE by the DCI. In other words, when the UE receives DCI relatedto the TCI states, the UE may recognize that the second PDSCH scheduledfor the UE (by the DCI or another DCI) is present, in addition to thefirst PDSCH scheduled by the DCI, so that the second PDSCH overlaps withthe first PDSCH on a time resource.

Accordingly, the UE may receive the first PDSCH (scheduled by the DCI)based on one of RS sets related to (i) the above assumption and (ii) theplurality of TCI states (S1620 and S1720).

Additionally, the UE may receive the second PDSCH (S1620 and S1720). Inthis case, the second PDSCH may be scheduled by the DCI or another DCIas described above.

The BS may transmit the first PDSCH (and the second PDSCH) to the UE(S1620 and S1720).

The UE may acquire related data information from the one or morereceived PDSCHs (S1630 and S1730).

In the above configurations, when the first PDSCH and the second PDSCHoverlap on a frequency resource as well as the time resource, the UE mayreceive the first PDSCH and the second PDSCH by differently configuringa first reception beam for the first PDSCH and a second reception beamfor the second PDSCH. In this case, the UE may configure the firstreception beam and the second reception beam based on the TCI states(and RS sets related to the TCI states) related to the DCI.

According to the present disclosure, the RS sets related to theplurality of TCI states may correspond to two RS sets. In other words,the DCI may be related to two TCI states and each TCI state may berelated to one RS set.

In this case, the one RS set for receiving the first PDSCH may bedetermined as the first RS set or the second RS set of the two RS sets,based on a CW number activated by the DCI. In other words, the UE mayconsider the CW number activated by the DCI to configure an RS set (orreception beam) for receiving the first PDSCH.

As an example applicable to the present disclosure, the one RS set forreceiving the first PDSCH may be determined as follows, based ondetermination that (i) the RS sets related to the plurality of TCIstates correspond to two RS sets and (ii) one or more DMRS portsindicated by the DCI are included in different CDM groups. In otherwords, the UE may consider a CDM group to which a DMRS port related tothe first PDSCH belongs in order to configure the RS set (or receptionbeam) for receiving the first PDSCH.

-   -   The one RS set for receiving the first PDSCH is determined as        the first RS set of the two RS sets, based on one or more DMRS        ports related to the first PDSCH, included in the first CDM        group.    -   The one RS set for receiving the first PDSCH is determined as        the second RS set of the two RS sets, based on one or more DMRS        ports related to the first PDSCH, included in the second CDM        group.

More specifically, when one or more DMRS ports related to the firstPDSCH are included in the first CDM group, the one RS set for receivingthe first PDSCH may be determined as the first RS set of the two RSsets. When one or more DMRS ports related to the first PDSCH areincluded in the second CDM group, the one RS set for receiving the firstPDSCH may be determined as the second RS set of the two RS sets.

In the example, the UE may receive the second PDSCH scheduled by theDCI. In this case, the second PDSCH may be received based on an RS setdifferent from the one RS set for receiving the first PDSCH among thetwo RS sets.

In the above example, the first CDM group and the second CDM group maybe configured as follows, based on a first DMRS configuration typeconfigured for the UE.

-   -   The first CDM group includes DMRS port #0, DMRS port #1, DMRS        port #4, and DMRS port #5.    -   The second CDM group includes DMRS port #2, DMRS port #3, DMRS        port #6, and DMRS port #7.

In the above example, the first CDM group and the second CDM group maybe configured as follows, based on a second DMRS configuration typeconfigured for the UE.

-   -   The first CDM group includes DMRS port #0, DMRS port #1, DMRS        port #6, and DMRS port #7.    -   The second CDM group includes DMRS port #2, DMRS port #3, DMRS        port #4, DMRS port #5, DMRS port #8, DMRS port #9, DMRS port        #10, and DMRS port #11.

As another example applicable to the present disclosure, based ondetermination that (i) the RS sets related to the plurality of TCIstates correspond to two RS sets and (ii) one or more DMRS portsindicated by the DCI are included in one CDM group, the one RS set forreceiving the first PDSCH may be determined as one specific RS set ofthe two RS sets, without considering the one CDM group.

More specifically, the specific one RS set for receiving the first PDSCHmay be determined as the first RS set or the second RS set of the two RSsets.

As another example applicable to the present disclosure, based ondetermination that (i) the RS sets related to the plurality of TCIstates correspond to two RS sets and (ii) one or more DMRS portsindicated by the DCI are included in one CDM group, the one RS set forreceiving the first PDSCH may be determined as the first RS set or thesecond RS set of the two RS sets, based on the one CDM groupcorresponding to a first CDM group or a second CDM group.

In a more specific example, according to whether one CDM group to whichthe one or more DMRS ports indicated by the DCI belong is the first CDMgroup or the second CDM group, the one RS set for receiving the firstPDSCH may be determined as follows.

-   -   The one RS set for receiving the first PDSCH is determined as        the first RS set of the two RS sets based on the one CDM group        corresponding to the first CDM group.    -   The one RS set for receiving the first PDSCH is determined as        the second RS set of the two RS sets based on the one CDM group        corresponding to the second CDM group.

In the present disclosure, overlapping of the first PDSCH and the secondPDSCH on the time resource may include scheduling of the first PDSCH andthe second PDSCH in at least one or more identical symbols.

In the present disclosure, all the above-described examples (inparticular, based on FIGS. 16 to 18) may be implemented incombination/association with each other unless they are incompatible. Inother words, the UE and the BS according to the present disclosure mayperform combined/associated operation of all the described examples (inparticular, based on FIGS. 16 to 18) as long as all the examples are notincompatible.

Since examples of the above-described proposal method may also beincluded in one of implementation methods of the present disclosure, itis obvious that the examples are regarded as a sort of proposed methods.Although the above-proposed methods may be independently implemented,the proposed methods may be implemented in a combined (aggregated) formof a part of the proposed methods. A rule may be defined such that thebase station informs the UE of information as to whether the proposedmethods are applied (or information about rules of the proposed methods)through a predefined signal (e.g., a physical layer signal or ahigher-layer signal).

3. Device Configuration

FIG. 19 is a diagram illustrating configurations of a UE and a BS bywhich proposed embodiments can be implemented. The UE and the BSillustrated in FIG. 19 operate to implement the embodiments of theabove-described DL signal transmission and reception method between theUE and the BS.

The UE 1001 may operate as a transmission end on UL and as a receptionend on DL. The BS (eNB or gNB) 1100 may operate as a reception end on ULand as a transmission end on DL

That is, the UE and the BS may include transmitters 1010 and 1110 andreceivers 1020 and 1120, respectively, to control transmission andreception of information, data and/or messages and may include antennas1030 and 1130, respectively, to transmit and receive information, data,and/or messages.

The UE and the BS further include processors 1040 and 1140,respectively, for performing the above-described embodiments of thepresent disclosure. The processors 1040 and 1140 control memories 1050and 1150, the transmitters 1010 and 1110, and/or the receivers 1020 and1120, respectively, to implement the above-described/proposed proceduresand/or methods.

For example, the processors 1040 and 1140 include communication modemsdesigned to implement radio communication technology (e.g., LTE or NR).The memories 1050 and 1150 are connected to the processors 1040 and 1140and store various information related to operations of the processors1040 and 1140. As an example, the memories 1050 and 1150 may perform apart or all of processes controlled by the processors 1040 and 1140 orstore software code including the above-described/proposed proceduresand/or methods. The transmitters 1010 and 1110 and/or the receivers 1020and 1120 are connected to the processors 1040 and 1140 and transmitand/or receive radio signals. The processors 1040 and 1140 and thememories 1050 and 1150 may be a part of a processing chip (e.g.,system-on-chip (SoC)).

The transmitters and receivers included in the UE and the BS may performa packet modulation and demodulation function, a high-speed packetchannel coding function, an OFDMA packet scheduling function, and/or achannelization function, for data transmission. The UE and the BS ofFIG. 19 may further include low-power radio frequency (RF)/intermediatefrequency (IF) units.

FIG. 20 is a block diagram of a communication device by which proposedembodiments can be implemented.

The device illustrated in FIG. 20 may be a UE and/or a BS (e.g., an eNBor a gNB) adapted to perform the above mechanism or may be any devicefor performing the same operation.

As illustrated in FIG. 20, the device may include a digital signalprocessor (DSP)/microprocessor 2210 and an RF module (transceiver) 2235.The DSP/microprocessor 2210 is electrically connected to the transceiver2235 to control the transceiver 2235. The device may further include apower management module 2205, a battery 2255, a display 2215, a keypad2220, a SIM card 2225, a memory device 2230, a speaker 2245, and aninput device 2250, according to the selection of a designer.

Specifically, FIG. 20 illustrates a UE including the receiver 2235configured to receive a request message from a network and thetransmitter 2235 configured to transmit transmission or reception timinginformation to the network. The receiver and the transmitter mayconstitute the transceiver 2235. The UE may further include theprocessor 2210 connected to the transceiver 2235 (receiver andtransmitter).

In addition, FIG. 20 illustrates a network device including thetransmitter 2235 configured to transmit a request message to the UE andthe receiver 2235 configured to receive transmission or reception timinginformation from the UE. These transmitter and receiver may constitutethe transceiver 2235. The network further includes the processor 2210connected to the transmitter and the receiver. This processor 2210 maybe configured to calculate latency based on the transmission orreception timing information.

Thus, the processor included in the UE (or a communication deviceincluded in the UE) according to the present disclosure and theprocessor included in the BS (or a communication device included in theBS) according to the present disclosure may control the correspondingmemories and operate as follows.

In the present disclosure, the UE may include at least one radiofrequency (RF) module; at least one processor; and at least one memoryoperably connected to the at least one processor, for storinginstructions for causing the at least one processor to perform aspecific operation when the at least one processor is executed. In thiscase, the communication device included in the UE may be configured toinclude the at least one processor and the at least one memory. Thecommunication device may be configured to include that at least one RFmodule or may be configured to be connected to at least one RF modulewithout including the at least one RF module.

The at least one processor included in the UE (or at least one processorof the communication device included in the UE) may be configured tocontrol the at least one RF module to receive DCI for scheduling one ormore PDSCHs, assume that a second PDSCH scheduled for the UE is presentso as to overlap with a first PDSCH scheduled by the DCI on a timeresource, based on a plurality of TCI states related to one referenceresource (RS) set, the plurality of TCI states being allocated to the UEby the DCI, and receive the first PDSCH based on one of RS sets relatedto (i) the assumption and (ii) the plurality TCI states.

The UE (or the communication device included in the UE) may beconfigured to communicate with at least one of a mobile terminal, anetwork, or a self-driving vehicle other than a vehicle in which the UEis included.

In the present disclosure, the BS may include at least one radiofrequency (RF) module; at least one processor; and at least one memoryoperably connected to the at least one processor, for storinginstructions for causing the at least one processor to perform aspecific operation when the at least one processor is executed. In thiscase, the communication device included in the BS may be configured toinclude the at least one processor and the at least one memory. Thecommunication device may be configured to include that at least one RFmodule or may be configured to be connected to at least one RF modulewithout including the at least one RF module.

The at least one processor included in the BS (or at least one processorof the communication device included in the BS) may be configured tocontrol the at least one RF module to transmit DCI for scheduling one ormore PDSCHs to the UE. In this case, a first PDSCH scheduled by the DCImay be configured to overlap with a second PDSCH scheduled for the UE bythe DCI or another DCI on a time resource. The at least one processorincluded in the BS (or at least one processor of the communicationdevice included in the BS) may be configured to control the at least oneRF module to transmitting the first PDSCH and the second PDSCH to theUE.

The UE in the present disclosure may use a personal digital assistant(PDA), a cellular phone, a personal communication service (PCS) phone, aglobal system for mobile (GSM) phone, a wideband code division multipleaccess (WCDMA) phone, a mobile broadband system (MBS) phone, a hand-heldPC, a laptop PC, a smartphone, or a multi-mode multi-band (MM-MB)terminal.

In this case, the smartphone refers to a terminal taking the advantagesof both a mobile communication terminal and a PDA and may be a terminalwhich incorporates functions of the PDA, i.e., a scheduling function anda data communication function such as fax transmission and reception andInternet connection, into the mobile communication terminal. The MM-MBterminal refers to a terminal which has a multi-modem chip therein andwhich can operate in any of a mobile Internet system and other mobilecommunication systems (e.g. a code division multiple access (CDMA) 2000system, a WCDMA system, etc.).

Embodiments of the present disclosure may be implemented by variousmeans, for example, hardware, firmware, software, or a combinationthereof.

In a hardware implementation, methods according to the embodiments ofthe present disclosure may be implemented by one or more applicationspecific integrated circuits (ASICs), digital signal processors (DSPs),digital signal processing devices (DSPDs), programmable logic devices(PLDs), field programmable gate arrays (FPGAs), processors, controllers,microcontrollers, microprocessors, etc.

In a firmware or software implementation, the methods according to theembodiments of the present disclosure may be implemented in the form ofa module, a procedure, a function, etc. for performing theabove-described functions or operations. For example, software code maybe stored in the memory 11050 or 1150 and executed by the processor 1040or 1140. The memory is located at the interior or exterior of theprocessor and may transmit and receive data to and from the processorvia various known means.

The above-described communication device may be a BS, a network node, atransmission terminal, a wireless device, a wireless communicationdevice, a vehicle, a vehicle having a self-driving function, an unmannedaerial vehicle (UAV), an artificial intelligence (AI) module, a robot,an augmented reality (AR) device, a virtual reality (VR) device, or thelike.

For example, the UE may include a cellular phone, a smartphone, a laptopcomputer, a digital broadcast terminal, a PDA, a portable multimediaplayer (PMP), a navigation device, a slate PC, a tablet PC, anultrabook, or a wearable device (e.g., a smartwatch, a smartglasses, ora head mounted display (HMD)). For example, the UAV may be an unmannedaircraft flying according to a wireless control signal. For example, theHMD is a display device wearable on the head, which may be used toimplement VR or AR.

Those skilled in the art will appreciate that the present disclosure maybe carried out in other specific ways than those set forth hereinwithout departing from the spirit and essential characteristics of thepresent disclosure. The above embodiments are therefore to be construedin all aspects as illustrative and not restrictive. The scope of thedisclosure should be determined by the appended claims and their legalequivalents, not by the above description, and all changes coming withinthe meaning and equivalency range of the appended claims are intended tobe embraced therein. It is obvious to those skilled in the art thatclaims that are not explicitly cited in each other in the appendedclaims may be presented in combination as an embodiment of the presentdisclosure or included as a new claim by a subsequent amendment afterthe application is filed.

The present disclosure is applicable to various wireless access systemsincluding a 3GPP system, and/or a 3GPP2 system. Besides these wirelessaccess systems, the embodiments of the present disclosure are applicableto all technical fields in which the wireless access systems find theirapplications. Moreover, the proposed method can also be applied tommWave communication using an ultra-high frequency band.

Additionally, the embodiments of the present disclosure are applicableto various applications such as a self-driving vehicle, a UAV, etc.

What is claimed is:
 1. A method for receiving a downlink signal by auser equipment (UE) in a wireless communication system, the methodcomprising: receiving downlink control information (DCI) includinginformation regarding a plurality of transmission configurationindication (TCI) states and information regarding a plurality ofDemodulation Reference Signal (DM-RS) ports within two or more codedivision multiplexing (CDM) groups including a first CDM group and asecond CDM group, wherein the plurality of TCI states includes a firstTCI state and a second TCI state, and wherein the plurality of DM-RSports includes one or more DM-RS ports for a first physical downlinkshared channel (PDSCH) within the first CDM group and one or more DM-RSports for a second PDSCH within the second CDM group; and receiving thefirst PDSCH and the second PDSCH based on the DCI, wherein the first TCIstate is related to the first CDM group and the second TCI state isrelated to the second CDM group.
 2. The method of claim 1, wherein thefirst PDSCH is received based on a reference signal (RS) set relatedwith the first TCI state, and the second PDSCH is received based on a RSset related with the second TCI state.
 3. The method of claim 2, whereinthe UE receives the first PDSCH based on a first reception beam for thefirst PDSCH determined based on the RS set related with the first TCIstate.
 4. The method of claim 1, wherein, the first PDSCH is overlappedwith the second PDSCH on a time domain.
 5. The method of claim 4,wherein the first PDSCH is overlapped with the second PDSCH in at leastone or more identical symbols.
 6. The method of claim 1, wherein, basedon the UE configured with a first DM-RS configuration type: the firstCDM group includes DM-RS port #0, DM-RS port #1, DM-RS port #4, andDM-RS port #5, and the second CDM group includes DM-RS port #2, DM-RSport #3, DM-RS port #6, and DM-RS port #7.
 7. The method of claim 1,wherein, based on the UE configured with a second DM-RS configurationtype: the first CDM group includes DM-RS port #0, DM-RS port #1, DM-RSport #6, and DM-RS port #7, and the second CDM group includes DM-RS port#2, DM-RS port #3, DM-RS port #4, DM-RS port #5, DM-RS port #8, DM-RSport #9, DM-RS port #10, and DM-RS port #11.
 8. A user equipment (UE)configured to receive a downlink signal in a wireless communicationsystem, the UE comprising: at least one receiver; at least oneprocessor; and at least one memory operably connected to the at leastone processor and storing instructions that, based on being executed,cause the at least one processor to perform operations comprising:receiving downlink control information (DCI) including informationregarding a plurality of transmission configuration indication (TCI)states and information regarding a plurality of Demodulation ReferenceSignal (DM-RS) ports within two or more code division multiplexing (CDM)groups including a first CDM group and a second CDM group, wherein theplurality of TCI states includes a first TCI state and a second TCIstate, and wherein the plurality of DM-RS ports include one or moreDM-RS ports for a first physical downlink shared channel (PDSCH) withinthe first CDM group and one or more DM-RS ports for a second PDSCHwithin the second CDM group; and receiving the first PDSCH and thesecond PDSCH based on the DCI, wherein the first TCI state is related tothe first CDM group and the second TCI State is related to the secondCDM group.
 9. The UE of claim 8, wherein the UE communicates with atleast one of a mobile terminal, a network, or a self-driving vehicleother than a vehicle in which the UE is included.
 10. A base station(BS) configured to transmit a downlink signal in a wirelesscommunication system, the BS comprising: at least one transmitter; atleast one processor; and at least one memory operably connected to theat least one processor and storing instructions that, based on beingexecuted, cause the at least one processor to perform operationscomprising: transmitting, to a user equipment (UE), downlink controlinformation (DCI) including information regarding a plurality oftransmission configuration indication (TCI) states and informationregarding a plurality of Demodulation Reference Signal (DM-RS) portswithin two or more code division multiplexing (CDM) groups including afirst CDM group and a second CDM group, wherein the plurality of TCIstates includes a first TCI state and a second TCI state, and whereinthe plurality of DM-RS ports include one or more DM-RS ports for a firstphysical downlink shared channel (PDSCH) within the first CDM group andone or more DM-RS ports for a second PDSCH within the second CDM group;and transmitting, to the UE, the first PDSCH and the second PDSCH basedon the DCI, wherein the first TCI state is related to the first CDMgroup and the second TCI State is related to the second CDM group.